Facebook's New Captcha Test: 'Upload a Clear Photo of Your Face' - <AUTHOR> https://www.wired.com/story/facebooks-new-captcha-test-upload-a-clear-photo-of-your-face/ <comment><USER2> Last paragraph of the article:

"The new authentication scheme is the second in recent weeks that relies on photos. Earlier this month, Facebook asked users to upload nude photos to Facebook Messenger, as part of an effort to prevent revenge porn. Facebook said it would use the nude photos to create a digital fingerprint against which to compare future posts."

Wait what? I had to check whether today was April 1st.

<comment><USER3> There was a thread about this on HN -- too lazy to look it up now or repeat some of the longer comments about it. But going into this assuming that FB has no ill-intentions, FB's proposal seems by far the best solution in a world of ugly and terrible solutions.

For starters, it's intended for victims of revenge porn, which is a fairly extreme category and one in which the harassment is distinctively aggressive and virulent. Because if it weren't, the way FB deals with abusive content generally would seem to be good enough. If you come into this thinking that FB is asking everyone to upload their nudes for "safekeeping", then you've missed the point.

Secondly, it's hard to think of an implementation that wouldn't create a potential disaster that justifies doing anything special for revenge porn victims. Using the Facebook app is the most secure channel for sending FB the photos because it is a secure app that all FB users know how to use. Having the user hash on their own requires either an external app or website.

I don't think it needs to be said how such ancillary applications can be spoofed. Even if only 0.5% of users are dumb enough to fall for these spoofs, each incident would be a complete fucking disaster, for the victims and for Facebook.

As for the prospect of FB owning people's nudes. Again, in the case of revenge porn victims, the horse is already far from the barn. If we assign the worst of motives to FB, that it's a way to secretly collect nudes from users. Again, horse, barn. This secret process would be less efficient by magnitudes compared to what FB can already do today.

<comment><USER4> FB has a no porn policy so wtf do you have verify you are you to get a revenge porn picture removed?

"We remove photographs of people displaying genitals or focusing in on fully exposed buttocks. We also restrict some images of female breasts if they include the nipple, but our intent is to allow images that are shared for medical or health purposes. We also allow photos of women actively engaged in breastfeeding or showing breasts with post-mastectomy scarring. We also allow photographs of paintings, sculptures, and other art that depicts nude figures. Restrictions on the display of sexual activity also apply to digitally created content unless the content is posted for educational, humorous, or satirical purposes. Explicit images of sexual intercourse are prohibited. Descriptions of sexual acts that go into vivid detail may also be removed." [https://www.facebook.com/communitystandards#nudity](https://www.facebook.com/communitystandards#nudity)

<comment><USER5> FB removes pornographic content, but it doesn't always do so proactively.

If a user shares pornographic content, it may be visible on the site for a short period of time before the content is removed by Facebook.

The goal of the initiative Facebook was attempting to implement was to prevent any revenge-porn photos from being shared on the website _at all_. Even for a brief period of time.

From a user's standpoint, one hour of pornographic content available is disturbing but not catastrophic. However, one hour of images of pornographic content of _themselves_ being shown to their friends and family is catastrophic.

<comment><USER6> I find the concept quite strange.

It's kind of like having the police live at your house because 'just in case'.

<comment><USER5> I realize this is a late reply, but I just saw this today.

I think the idea isn't that this is a "just in case" service. More like, if someone sends you a message that they've got compromising photos of you and will release them unless you pay $XX,XXX then you would use the service.

In the analogy, it'd be more like having the police live at your house after having a credible threat made against your life. Which is a thing that happens

</comment></comment></comment></comment></comment></comment><comment><USER7> Instagram did this same bullshit to me when I signed up for an account to to follow some photographers.

'Please provide a clear photo of yourself holding your government issued ID, and a piece of paper with the following code handwritten on it'.

No, fuck that for a joke.

There's this growing trend of everyone wanting your photo and some ID, and then you have no way to verify that information is being kept securely or used for appropriate reasons.

<comment><USER8> This is the KYC (Know Your Customer) laws. Online-only banks like Ally and Simple require the same thing.

In fact, every bank requires this. If you opened a bank account in-person some years ago you may not remember but they asked you for your government-issued ID card.

It's the same thing.

<comment><USER9> I have opened several bank accounts online and never have been asked for photo id. SSN and some knowledge-based auth sure, but no photos.

<comment><USER10> SSN and knowledge based auth are sometimes sufficient depending on where you fall against the company's risk model.

KYC processes are a type of situation where it is not a good idea to extrapolate all people's experience from one person's. The underlying mechanisms intentionally vary from person to person.

</comment></comment></comment></comment><comment><USER11> Sure, Facebook might delete your photo when they're done, but they probably won't delete any machine learning models that they trained using it.

<comment><USER12> wording like this is really tricky (intentionally so!), it exploits our naive notion of digital information as files. One aspect is the machine learning you mention but basically they can also create a new "file" from your image with metadata about your image. Metadata rich enough to render the original image unnecessary. There is no way out of this relatiohship with FB, however they formulate words to comfort you, there is always a different unexpected side to what they are saying..

<comment><USER13> The more data they keep about these images that they are promising to delete, the more they would make themselves liable to be sued for privacy violation (especially in the EU).

It is a blurred line, but one that most rational companies (=not Uber) would prefer to avoid in the first place by only storing data that is necessary for their main functionality.

<comment><USER14> What is Facebook's "main functionality"?

<comment><USER15> Monetizing on people's relationships and social addiction, collecting and providing detailed data on all user activities, sentiments and connections, selling sets of such data to ...?

<comment><USER16> Advertisers. If you've ever bought an ad on facebook and see you can pick your target audience by which types of food they shop for or their income range from 10k increments alongside thousands of other filters.... fuck man they have a helluva ad platform

</comment></comment></comment></comment></comment></comment><comment><USER17> I used to think richard stallman was just a paranoid lunatic... Well, the more time goes by, the more i think he was just 100% right. It's time to be much much more careful and radical with the path technology is taking us.

It's time we all invest a bit of our time to provide real open and benevolent alternatives to facebook, google, amazon, and all the rest, because they're steering internet toward an orwelian nightmare.

<comment><USER18> Network effects. You and me care. Sadly the vast majority around us bow unquestioningly to demands made by powerful groups like their govt or huge mega-corps. People seem to think these power-centres will always be benevolent and flawless... which history shows is a big mistake to assume.

<comment><USER17> I wouldn't put a democratic government on the same level of danger than profit driven mega corps. I'm pro free market, but some corps have reach state-level impact on people lives, and they remain without any kind of overview.

I also don't want state-run web sites to try to provide alternatives to Google ( like europe tried to do 10 years ago), so i think the foundation model is the perfect structure for that. Economically responsible, but not profit driven.

</comment></comment></comment><comment><USER19> I will never do this. I don't even post photos of myself on FB, or use "Messenger" or their mobile app, so it probably wouldn't work anyway, but I have no doubt they're looking to monetize the feature and that businesses and governments are their target markets.

<comment><USER20> They still have your face from scanning your friends' photos and contacts. Combine datestamp, location, messages, and posts over years and Facebook knows who was together for a photo whether or not you've uploaded any or been tagged. Facebook knows the face of everyone who is on Facebook or who knows a few people who are.

<comment><USER21> I can pull a fingerprint off the subway stair rails but that doesn't mean I can identify who it is. We anonymously reveal ourselves everyday but the danger comes from confirming which data is ours. The goal is to make it difficult not impossible.

<comment><USER22> They don't need you to confirm it. This isn't a criminal case. They just need to be reasonably confident. Your face is in a picture with four other people. They can see that phones belonging to four people, who regularly chat with each other, were all at the same location at the time the photo was taken. They are now reasonably confident that your face is one of those four. Do that five or six times and their robots will know your face. Whether you confirm it or not doesn't really matter.

<comment><USER21>
      They can see that phones belonging to four people, who regularly chat with each other, were all at the same location at the time the photo was taken.

How would they "see" your phone without the facebook app installed?

<comment><USER22> They buy/rent that data from google or any of a thousand other companies that might have access to your phone's location.

</comment></comment></comment></comment></comment></comment><comment><USER23> I should write a blog post about this, but to those thinking about deleting Facebook,

My experience deleting it 5 years ago is summarized as: my friend count went way down, my friend quality went way up.

Your results may vary, but the purpose of my comment is not to immediately be worried that Facebook is a mandatory lifeline for your social life.

<comment><USER24> A few years ago I walked away from Facebook. Three months later, I got a phone call from my mother (who's not online) because she heard through the grapevine that I was dead. My stupid Facebook "friends" took my silence for something sinister and jumped to conclusions.

I ended up returning to Facebook and purging my "friend" list down to just a dozen actual friends.

<comment><USER25> Really? Wow.

I always wondered what my Facebook acquaintances thought when I left.

I figured they didn't care Id left to give it much thought or that I was being a prick and had deleted them.

<comment><USER26> Most of my facebook "friends" didn't even noticed I've quit some months ago. For those that ask, I say that it consumed too much battery..

</comment></comment></comment></comment><comment><USER27> [https://petapixel.com/2017/11/07/ai-creates-photo- realistic-...](https://petapixel.com/2017/11/07/ai-creates-photo-realistic- faces-people-dont-exist/)

Tadaa. Another pointless privacy invasion that only affects the fair and honest.

<comment><USER28> Hmm, this wouldn't help you defeat the system at all, unless I'm missing something. What you need is a model to generate photos of _your_ face.

<comment><USER29> FB is most likely trying to ward off spammers with this idea. Generating unique faces per spam-bot is easy now, for sophisticated spammers, then for every spammer in a few months. The poster is trying to say that this FB effort won't work well and is already only adversely affecting the most stupid and trusting.

<comment><USER28> Good point, I was only considering the case where FB uses this technique to verify an existing user's identity using facial recognition (which seems like a "logical" use case).

I missed the part where they said they might use it for account creation as well (which makes less sense and seems like a pretty baroque, intrusive and ineffective captcha).

</comment></comment></comment></comment><comment><USER30> >"Please upload a photo of yourself that clearly shows your face. We'll check it and then permanently delete it from our servers."

>"To determine if the account is authentic, Facebook looks at whether the photo is unique."

The two statements are a bit contradictory. They might delete the photo but they won't delete its signature/fingerprint, because they need the later to check for uniqueness of other accounts.

<comment><USER31> Count your blessings. They could have additionally asked for a picture that "clearly shows your genitals".

Anywho, once the 'revenge porn' crowd starts hacking around this by chopping the said head from the said images, the central servers of FB are sure to ask for pics of genitals.

<comment><USER32> > Count your blessings.

No.

Facebook is not the Almighty God.

</comment></comment></comment><comment><USER33> I uploaded a cropped/mirrored picture of Jack Nicholson in the Shining. After 48 hours the account was working again, no idea what happens in that process.

<comment><USER34> Well, it's rather disappointing that they didn't catch something as simple as that ;)

It's already nontrivial to create fake Facebook accounts. For those serious about it, who already deal with IPs and mobile numbers, I can't imagine that creating novel photorealistic faces would be all that problematic.

<comment><USER35> Not that surprising; can you recognize random Bollywood stars?

</comment></comment></comment><comment><USER36> Facebook already locked me out of my account asking for it and since I'll never send it I guess I can finally stop using it... thanks facebook

</comment><comment><USER37> Is anyone concerned enough with their facebook profile security to want to be verified on this level?

why not a normal 2fa? it seems like there is a hidden agenda behind collecting and analyzing users facial characteristics.

<comment><USER38> Knowing fb, this is for their benefit, not the users i.e, they're trying to catch spammers and fake accounts, not see if you're the one accessing your own account or not.

<comment><USER39> I fear it's much more insidious than that. Facebook has a tendency to start doing some invasive stuff and then announce it to the world only 5 years later.

They probably plan to use your facial profile for a number of things, none of which have to do with authenticating you to the Facebook website. I even see them sharing the profiles with the DHS to build more accurate facial recognition at airports, and other stuff like that. But of course they wouldn't admit it now, because it would mean everyone refusing to use it from day one.

No wonder Facebook's attempt at getting people to give them their credit cards to enable ecommerce on the platform has been such an utter failure. The most popular searches on Google on this issue are whether or not you can trust Facebook with your credit card data.

That's happening for a reason - Facebook has _consistently_ tried to build a reputation of "shady-as-fuck" company throughout the years, and it's going to pay the price for it, either through stuff like people rejecting its ecommerce platforms, which means fewer billion-dollar monetization opportunities for Facebook in the long-term, or simply stopping using it when they get tired of the company's practices.

<comment><USER40> > I fear it's much more insidious than that. Facebook has a tendency to start > doing some invasive stuff and then announce it to the world only 5 years > later.

> They probably plan to use your facial profile for a number of things, none > of which have to do with authenticating you to the Facebook website. I even > see them sharing the profiles with the DHS to build more accurate facial > recognition at airports, and other stuff like that. But of course they > wouldn't admit it now, because it would mean everyone refusing to use it > from day one.

This validates my little project of uploading a ton of stock photos to my Facebook account and tagging myself in them.

<comment><USER41> make something automatable with browser plugin on github .. that does sounds interesting.

</comment></comment></comment></comment></comment><comment><USER42> They say they will permanently delete it off of their servers, but the numerous cases where they lied about deleting account information doesn't exactly engender a feeling of trust.

<comment><USER29> A friend does HW for Seagate servers and has talked a bit about the 'math' of servers. The reality is the FB may or may not delete the pics, no matter what they think they really did. With the amount of servers they utilize, one is failing about every second, permanently erasing all the data on it. Yes, back- up servers, and copies of the data. Still, a lot of data is getting trashed every second. So, they may be trying to weasel these pics, but do not trust that they are smart enough to get around the hard facts of server decay. If they are being honest, then there is still no way to determine if some back-up somewhere actually is storing the data, despite their best efforts. The code stack for something like FB is so huge, there really is no way of knowing where a piece of data is or isn't. Kafka would be beaming at it's absurdity.

In addition, they also have a lot of 'fresh' servers out there, spinning about for months, not being written to, as some algorithm works it's way around using the fresh servers. These also fail, having never been used. Seagate does not mind when companies like FB do this nonsense.

</comment></comment><comment><USER43> Question: is Wired actively blocking archive.is? I tried to archive this article just to get a repeated "Network error" [1] which may be a sign of a Layer 3 block. A trivial search [2] shows no page is successfully archived since the end of September.

[1] [https://archive.is/eU7Yn](https://archive.is/eU7Yn)

[2] [https://archive.is/www.wired.com](https://archive.is/www.wired.com)

</comment><comment><USER44> I was recently locked out of my FB account. The only way to unlock it was to identify my friends' pictures. Apparently sending me an e-mail was too much trouble ...

Haven't been able to log in since, as I refuse to partake in that sort of bullshit. Can't say I miss it.

<comment><USER45> What do you have against identifying friends' profile images, of all things? Facebook already has them.

<comment><USER46> If one of my friends identified me in a photo to facebook, I would not be happy about it.

I generally ask everyone who knows me not to upload photos I'm in to facebook at all beyond what's already there.

<comment><USER47> Exactly, the point it validates and updates the current status of friendship you have. Further it informs facebook who are the people you really know opposite to your "facebook friends" .

</comment></comment></comment></comment><comment><USER48> I mean you need to pick your poison here. You either give facebook more data to validate your authenticity or you allow botnets to influence the social networks. It seems impossible to have it both ways, although I'm willing to hear alternatives in the general case.

<comment><USER49> Authenticity validation could be _completely_ external from Facebook, and if they gave a shit about your privacy they would not only be OK with it but even push for it.

Many countries already have crypto-secure solutions for verifying their identity when submitting things like tax forms. Facebook just needs to start using them, but they won't, and it's obvious why.

<comment><USER50> No. This is the absolute wrong direction and would likely help push for a Government Internet ID. This would complete destroy online anonymity.

<comment><USER49> The US isn't the world. "Government Internet IDs" already exist, and there is nothing inherent in them existing that eliminates online anonymity, it just removes it on Facebook (which is exactly the point).

<comment><USER50> Imagine having to use your government ID to even connect to the internet. Having all your data logged and cataloged to your ID. At one point in time that is what the US government wanted to do. It starts by normalizing the action. Not a world I want to live in.

<comment><USER49> You're completely de-railing the discussion and trying to respond to this nonsense in any constructive way would only de-rail it further. No amount of strawmen and US-centric "the government wants to enslave us all" propaganda will make me think that the now existing, well working digital ID systems available in the world (not the US) are the work of the illuminati, should be abolished, and/or will be surgically inserted into my brain in the near future.

I made a point that there are already ways for Facebook, in certain countries, to verify the identity of their users, if they so please; and that Facebook will never use these because they'd rather control the system of verification themselves (prioritizing profit, not privacy and integrity of users). They could use the systems already in place and say "you know what, the state of Estonia is telling us this guy is who he says he is, we'll accept that". What you're doing is arguing against government-backed digital identification in any broad definition of the term, and you can have that opinion but it's off topic.

</comment></comment></comment></comment></comment></comment><comment><USER51> If it can't be fooled by a picture found online (but not uploaded to facebook) then that must mean facebook is indexing images across the internet and analysing all the faces they find... and if it can, what's the point (edit: from a user point of view)?

<comment><USER52> To have the world's best biometric registry that is constantly updated and optimized by it's users.

<comment><USER51> Yes, I should have been more accurate in my original post - what's the point for the user :-)

<comment><USER53> This doesn't exist to benefit the user. This exists solely to benefit Facebook.

</comment></comment></comment></comment><comment><USER54> I find their claim that the picture will be deleted from their servers at odds with their claim that they will make sure that photo is unique.

I suspect that what they're not saying is that they will keep some signature/hash/data about the photo, which I'm sure they will use for much more than just verifying uniqueness.

<comment><USER55> Yep, that's in the article. They say they'll hash it and delete it (the photo). They don't claim they'll delete the hash. Having the hash is enough to check for uniqueness. Although it's sort of an over-strict definition of uniqueness. Example: I change one pixel → That produces a drastically different hash → That makes the almost-identical photo seem unique.

I'd be surprised if they weren't extracting other info from the photo or training ML models on it as others suggest here.

<comment><USER56> > I change one pixel → That produces a drastically different hash

If they're hashing the raw bytes, sure. If they're hashing a representation of the face that encodes meaning (like the relative locations of facial features), then changing one pixel is unlikely to affect that.

<comment><USER55> Indeed - lots of things could be concealed in that phrase "the photos are hashed!"

</comment></comment></comment></comment><comment><USER57> This is literally the name of the company

</comment><comment><USER58> Are they allowed to sell the "fingerprint" packaged with your name to advertising agencies? If so it should only be a matter of time before those Minority Report inspired advertising screens start popping up everywhere..

The advertisers can always protect that system with some DRM to get the mighty DMCA on their side. That way they don't need to build a robust solution and can still wipe their hands clean if they loose it all to a 12 year old script kiddie.

</comment><comment><USER59> >> "Please upload a photo of yourself that clearly shows your face. We'll check it and then permanently delete it from our servers."

>> To determine if the account is authentic, Facebook looks at whether the photo is unique.

I assume this means that the photo itself is deleted but a one-way hash of it created to test against later.

However, if I change one pixel of a picture of my face, A, to produce a new picture of my face, A', the hash of A' will not be the same as the hash of A, correct? And I can repeat this process n x m times, where n, m the dimension of the image, ja?

Additionally- when they say "unique", do they mean "known as unique" to Facebook, or "unique in the entire world"? If I take a picture of myself and put it on, dunno, my blog on Blogger, what's stopping someone copying it and uploading it to Facebook to pretend it's me? Will Facebook search the entire web for images potentially matching an uploaded image?

For the record, I don't use Facebook. And there are no pictures of myself anywhere on the internets. As if.

<comment><USER60> Hashes don't necessarily work on the raw bit representation of something. You can have a hash which works on higher level constructs, which for images one solution would be called a perceptual hash.

<comment><USER61> I thought the accepted term for this was "fingerprint" not "hash".

<comment><USER60> Hashes produce fingerprints(including perceptual hashes). Most people are talking about cryptographic hash functions when talking about 'hashing' but that is just one type.

There is a wikipedia page for 'perceptual hashing' as well as a number of libraries available which claim to do perceptual hashing, so it may just come down to what kind of crowd you roll with :)

</comment></comment></comment></comment><comment><USER62> I'm sure the biometric data harvested from these pictures won't be abused by three letters agencies.

<comment> GCU-Empiricist You forgot your /s

</comment></comment><comment><USER24> Straw, meet camel's back.

I'll give up Facebook before I give up that level of privacy.

</comment><comment><USER63> >"The company declined to share details to prevent the system from being manipulated. Suspicious activity might include someone who consistently posts from New York and then starts posting from Russia."

So in others words people who travel or go on vacation?

<comment><USER64> Numerous systems that scrutinize IP-based geolocation information already throw up additional security checks when detecting changes.

Personally I welcome it, especially when banks do it. It's low-hanging fruit TBH. It massively fucks with those using VPN or Tor but I'm fine with that.

<comment><USER63> Except that FB isn't a bank and doesn't store one's financial data.

Also this argument falls flat as we are an increasingly mobile population whether that be travel for pleasure or business.

I remember watching in amusement/horror as a friend I was traveling with in Thailand wasn't able to access her Facebook account unless she verified via her phone that she was actually attempting to log into her account from Thailand. It's like you're supposed to check in with Facebook and let them know where you are. So creepy.

<comment><USER65> What sort of ridiculous nitpicking is this? First, FB does have a Payments feature, so if you are being pedantic, it does deal with one's financial world.

Second, for a lot of people, their FB profile has a lot of confidential information, and is tied to their personal identity so they can't have the risk of it being compromised based on leaked passwords or whatever. It may not matter for you, but I am happy that they are safeguarding my account just the way a bank would.

<comment><USER63> There's nothing nitpicky in anything I wrote. FB is not a bank. And it can not be used as someone's financial institution.

>"Second, for a lot of people, their FB profile has a lot of confidential information, and is tied to their personal identity so they can't have the risk of it being compromised based on leaked passwords or whatever."

Who puts "confidential information" on FB?

FB is based on the premise of voluntarily sharing" information. If people are willing to share information on a social networking site it can't really be considered "confidential" or even "sensitive" to you can it?

Also FB is not one's identity, despite what FB would like you to believe that it is.

</comment></comment></comment></comment></comment><comment><USER66> feels like this could be easily bypassed with something like this [https://www.theverge.com/2017/10/30/16569402/ai-generate- fak...](https://www.theverge.com/2017/10/30/16569402/ai-generate-fake-faces- celebs-nvidia-gan)

</comment><comment><USER67> All that spammers have to do now is to upload other people's photos first.

Imagine the surprise we'll have when we'll find out our accounts were cloned.

</comment><comment><USER68> What do you think Facebook could do here, that wouldn't violate privacy, to verify that you are who you claimed to be?

</comment><comment><USER69> This is outrageous invasion of privacy. Facebook must die.

</comment><comment><USER70> I have to say: as much as I probably agree with every critic of this… The damn thing is called FACEbook, so it would almost be wrong for them _not_ to do this!

(I don't know a mark for whatever this is, it's not sarcasm or irony, something about tragic comedy fate…)

</comment><comment><USER71> AirBnB does this today, had to go through the process a few weeks ago to create an account to book a room! And of course the process failed,.. and of course we thought we were going to miss out on our room booking,.. and of course I now really dislike airBnB

</comment><comment><USER72> Sorry, I don't understand, but wouldn't someone ( suspicious ) also have a photo of yours if they have the access to your account. They could easily upload that photo and pass the captcha test .. Or am I missing something?

<comment><USER73> If I understand it correctly they would have to provide a photo with your face that FB hasn't seen before. Still rather easy to obtain for the determined.

</comment></comment><comment><USER74> Facial verification, together with cell phone number, which requires an ID to purchase, has been the standard practice for internet companies in China for a while now, e.g. for WeChat, Alipay, etc.

</comment><comment><USER75> Applies to most of the biggies: Since i am a behemoth of tech, give me all your personal info and surrender yourself. I will tell you what you should see, eat, buy, think & whom you should be-friend! In return your everyday personal data is my asset, my asset only! Its up to me how i use your personal data. NO QUESTION SHOULD BE ASKED! Remember you have signed the agreement (Privacy Policy)!

</comment><comment><USER76> Just upload a picture of one of the millions of people that haven't cleared this hurdle yet and the problem is on somebody else's plate.

</comment><comment><USER77> Ok, but would it work against generative network generated faces? cf. [https://towardsdatascience.com/implementing-a-generative- adv...](https://towardsdatascience.com/implementing-a-generative-adversarial- network-gan-dcgan-to-draw-human-faces-8291616904a)

</comment><comment><USER78> So right around we when start exploring the dumpster fire of of SSNs and personal data collection with Equifax and the entire credit reporting / financial industry, a new form of personal data collection as well as mixing up identification and authorization arises ... (I blame Apple too...)

</comment><comment><USER79> Uber does this for their drivers to confirm it's the registered person driving the vehicle.

</comment><comment><USER80> Apart from possible biometrics collection, it is Facebook that now decides how do you behave and what to grant you for your behavior. Like Santa for adults.

Maybe it's time to open your eyes and see that there is no Santa since 1984?

</comment><comment><USER81> This isn't very future-proof. Computer graphics today can produce human faces that are extremely realistic. Someone will make a random-face generator, and a bot will pipe random faces to Facebook.

</comment><comment><USER82> You would think that for captcha purposes (ie. a unique, quickly produced, creative item) it would suffice to say "draw a picture of a dog" (or "upload a clear photo of your hand").

</comment><comment><USER27> I want to create a library for generating photos of computer-generated faces

</comment><comment><USER83> > The process is automated, including identifying suspicious activity and > checking the photo. ... The Facebook spokesperson said the photo test is one > of several methods, both automated and manual, used to detect suspicious > activity.

So I don't get if this "captcha" process is automated or manual (...or both)? Somewhere else in the article it says that users are apparently locked out of their accounts until the pic is verified. Seems odd that there should be a lock-out period if the process is automated (as the first sentence of the above quote implies).

ALSO, for a captcha, isn't this dead easy for bots? Get a DeepDream/Generative Adversarial Network instance to generate faces for you. Bam. This is not a barrier.

<comment><USER84> Couple things.

1.) The face verification is automatic. It is among other processes that are automatic and some other processes that are manual.

2.) Lock out periods are to prevent repeated attempts.

3.) The face has to match the face of the account, so generating a new face won't work.

<comment><USER83> Where was it specified that lock-outs are to prevent repeated attempts? It is a plausible reason but the premise of my question (and confusion as to whether this process is automatic or not) stems from:

> ...users are locked out of their accounts _while the photo is being > verified_. A message said, "You Can't Log In Right Now. We'll get in touch > with you _after we've reviewed your photo_. You'll now be logged out of > Facebook as a security precaution."

Emphasis mine.

"after we've reviewed your photo" \--> FB can autotag people as pictures are uploaded. Surely they can verify face similarity instantly?

</comment></comment></comment><comment><USER85> i signed up with facebook (with a unique email), and encountered this. i used a picture (a painting, rather) of george washington.

it seemed to work at first, but when i tried logging in a month or two later my account was disabled. perhaps i wasn't the only person using that image and they were displeased.

</comment><comment><USER86> This is a classic example of technical staff not thinking about what a user would do.

</comment><comment><USER87> No. Like Nancy Reagan said, "just say no."

Your likeness is your data.

</comment><comment><USER88> Like it's hard to get a bunch of photos of real faces?

</comment><comment><USER89> The next level would probably be: provide your SSN.

<comment><USER90> Experian probably already shared that with them.

</comment></comment><comment><USER91> Ah biometrics, the password you can't change

</comment><comment><USER92> Eject eject eject

Abandon ship.

Or abandon Facebook. .

</comment><comment><USER93> I read at first "China's New Captcha Test".

</comment><comment><USER94> Because if you were accessing someone else's Facebook account you wouldn't have access to a whole bunch of photos of their face would you.

</comment><comment><USER95> maybe this is how skynet starts

<comment><USER96> Skynet is entertainment. A real ASI will be much more proficient at removing threats.

Both nanobots and a genetically engineered super virus, for example, would be very well suited to extinguish humanity in a timeframe that makes resistance / retaliation impossible.

Now if I as a dumb human can come up with that, just imagine what a being incredibly smarter than anything we could imagine could come up with.

</comment></comment><comment><USER97> That's not a captcha, that's used when you're locked out of your account and they need to verify if it's you. Like when they ask for your ID card.

I assume this only happens if you've uploaded pictures of yourself in the past, so they can compare them.

<comment><USER98> Uh, the article disagrees.

> In a statement to WIRED, a Facebook spokesperson said the photo test is > intended to "help us catch suspicious activity at various points of > interaction on the site, including creating an account, sending Friend > requests, setting up ads payments, and creating or editing ads."

They're basically training people to provide PII/biometrics on-demand as the price of using their service.

</comment></comment><comment><USER99> Its good to have better security features.

</comment><comment><USER100>
      big brother zuckerberg

<comment><USER101> Zuck: People just submitted it.

Zuck: I don't know why.

Zuck: They "trust me"

Zuck: Dumb fucks.

[https://news.ycombinator.com/item?id=1349934](https://news.ycombinator.com/item?id=1349934)

</comment></comment><comment><USER84> This doesn't seem too weird considering the service is called "face" book, and the point is to upload photos of your face. They have been using facial recognition for years now, this is a natural extension of that.

I am not a user, but I see the value. It's creepy as hell, yes, but I see the value.</comment>


Solutions for free via Job Interviews - <AUTHOR> http://mdshannan1.blogspot.com/2011/10/solutions-for-free-via-job-interviews.html

<comment><USER2> Funny, I was imagining almost this exact same scenario the other day. I thought it would be a good way to see how well the interviewers collaborate. I suppose it depends on how honest everyone is about what's going on.</comment>


What's Next for Gitlab CI: Auto DevOps - <AUTHOR> https://about.gitlab.com/2017/06/29/whats-next-for-gitlab-ci <comment><USER2> "Gitlab dominates" 5% of the hosted market vs 95% of the SaaS market. And their reported popularity is based on data from a single CI company. This is further skewed since it's one of a few CI tools that actually supports Gitlab as an OAuth provider.

There's no way this claim would stand up to any scrutiny or more data- gathering. It's just marketing fluff.

EDIT: More on what upset me about this claim.

First, we have no idea of what the composition of the 10,000 applications Bitrise surveyed are like. There could be a single company that uses Gitlab to test thousands of applications that completely invalidate this result.

Second, this insults my (and every other competent readers') intelligence. This is badly done marketing. And their audience is developers. So they know they're misleading us but I guess they don't care.

<comment><USER3> Stats don't make much sense. Self hosted bitbucket is huge.

I've worked for Atlassian companies lately but none of their crap calls out to the Internet and tells the mothership what they're up to. Well I guess they do. But not in a way that other people can tell. Totally not an Atlassian shill (often I wish we had gitlab) but their stuff works self hosted real well.

There's no way a third party could know what the numbers are, because when you use software which doesn't sell you out, well, you're not sold out.

</comment></comment><comment><USER4> I really like the core of gitlab. It's a really good git hosting system that is easy to maintain and work with. My self hosted instance has broken only twice in the last 1.5 years and it was always because of an upgrade and it was always easily fixed.

But now i have to say i'm afraid gitlab is getting bloated. Why not keep the core product as a seperate thing from things like CI? a simple plugin style system would be enough for it to not feel like bloat but feel like extra options.

<comment><USER5> I just updated the NixOS gitlab package from 8 to 9[0]. It was a nightmarish experience. There are 5 microservices :

\- gitlab (the core)

\- gitlab-sidekiq (a work queue)

\- gitlab-workhorse (provides the frontend)

\- gitaly (a git wrapper that caches stuff)

\- gitlab-shell (a shell spawned when doing your git clone)

Those are written in either go or ruby. Sometimes mixing the two in the same repository. In the main gitlab repo, there is also some unvendored js dependencies for the frontend, necessitating to jump through some more hoops.

Gitlab has a bunch of hardcoded paths to logfiles and config files. Some config files are toml, others are yaml. Different services need different configs, sometimes duplicating the config entries in a different format.

I love gitlab as a product. But as a sysadmin, it's one of the worst thing I've ever had to deploy.

[0]: Well, it's not pulled there, but it's at [https://github.com/NixOS/nixpkgs/pull/27159](https://github.com/NixOS/nixpkgs/pull/27159) if you're interested.

<comment><USER6> Please use the official Omnibus packages to ensure that upgrades are less likely to break.

I think we use toml for the Runner since it is written in Go and should be deployed on another server. The rest is mostly in yml files although we trying to move as much as possible to the UI to make it more user friendly.

<comment><USER7> _> Please use the official Omnibus packages to ensure that upgrades are less likely to break._

That would be almost precisely against the whole idea of NixOS.

</comment></comment></comment></comment><comment><USER8> "Gitlab dominates self-hosted git"

Dont you mean, Gitlab,

"2/3 of people surveyed by Bitrise, a CI service you may have never heard of, which is free, are using Gitlab, which is also free"

<comment><USER9> The two statements are not mutually exclusive.

<comment><USER10> Neither implies the latter the former.

</comment></comment></comment><comment><AUTHOR> OP here, just to note - I'm not an employee or affiliated with Gitlab in any way (outside of considering working for them once) -- just a rabid fan.

I've been at companies where I've tried (and failed) to convince other developers/higher ups that something like automatically creating an instance of an app based on the feature branch (what Gitlab/others are calling a "review-app"), is the best way to test individual features with high velocity (of course, this requires one more integration level test in the staging environment to make sure everything works together well). I'm impressed/awed/grateful that Gitlab is pulling these features into their 100% open source solution.

The most common complaints against gitlab are:

\- Gitlab's UI is bad-ish (this is what made me consider going to work there/contributing and helping fix that)

\- Gitlab is slow

And I think they're dumb. If you think UI on your code hosting tool and slow file operations (on the order of minutes, not hours) to be what would slow their org down, instead of the fact that you haven't automated things that Gitlab wants to automate for free for you (like test deployments actual deployments, build steps), in one coherent place (no juggling github, jenkins, jira, whatever else) then I think you're wrong.

<comment><USER11> I work with self-hosted Gitlab daily and I've never thought the UI was bad or slow. In fact, I think it works pretty well.

To the other commenters: Do you have any examples?

Also, I'm excited about auto deployment. The less tools one needs to get software shipped, the better.

<comment><USER12> To see that the UI design is bad at times, take the design of merge requests and issues for example.

On Github you can easily see what happens, comments are surrounded by a black border, the name of the comment author and the date are clearly visible and have a different background color from the comment text. Actions like closing and re-opening are distinctly different from comments and are color coded (green -> re-opened, red -> closed, purple -> merged). Emoticons are part of the comment box and don't visually drift into the next one.

Gitlab on the other hand separates comments by a thin (1px) light-grey line that is hardly visible on low contrast monitors like TN displays. Closing and re-opening is also displayed as a light-grey icon on a white background. The author's name has the same color as the comment text, with the date being, again, light-grey. Nothing keeps the contents of a comment together, it's all just text on a white background. The emoticons are just floating around the comments, with the same margin to the next comment as to the comment they are belonging to. So you have to _know_ that emoticons are always below a comment.

Github's design is far, far superior to Gitlab's design because it allows skimming instead of concentrating on finding where each comment begins and ends.

<comment><USER13> I appreciate the thoughtful and specific feedback. We are working hard to make merge requests and issues intuitive and easy to work with. Many of your observations regarding merge requests are being worked on as part of this issue: [https://gitlab.com/gitlab-org/gitlab- ce/issues/33095](https://gitlab.com/gitlab-org/gitlab-ce/issues/33095)

<comment><USER12> I'm really sorry that I cannot help by posting this on your issue tracker but I don't have the time right now to sift through all relevant issues on Gitlab to find out where to post and what already has been posted.

My biggest gripe is just that the issue elements (comments, actions, label changes, description edits) are looking too similar for a quick glance. The light-grey font on a white background makes it pretty hard. My suggestion would be to do it a bit like Gihub and to add a black border around stuff, take another background color for actions, and get rid of the grey font and replace it with black throughout.

</comment></comment></comment></comment></comment><comment><USER14> I would imagine that git dominates self-hosted git.

I just have bare repos on servers I can ssh into. End of problem.

<comment><USER15> Of the 2 employers I've had who self-hosted, they both did this. I've also done this when self hosting, it's super easy.

I guess there are probably no surveys of this though...

<comment><USER16> It's super easy for you. I tried to set this up but it's such a pain in the backside to tell people how to pull the latest code. Ended up with Gitlab and haven't looked back.

I didn't even realise Gitlab doesn't have auto-deploy yet.. We set up a .gitlab-ci.yml script that deploys the code.

</comment></comment></comment><comment><USER17> We've been on Gitlab since version 5 and for the most part it's been a pleasure to work with. The omnibus version has made things way easier to install/upgrade, so not sure what the fluff is about being hard to maintain. The UI is adequate and they are working on improvements to smooth out the rough edges a bit. Looking forward to the improvements and new features to come. Just wanted to post something positive instead of the nit picky hate I've been seeing lately about Gitlab...

</comment><comment><USER18> I always use [http://gitolite.com](http://gitolite.com), thats enough.

nb: I dont see the point of the graph about numbers of questions on SO. A high level of questions = A lot of problem, no :)?

<comment><USER19> I really like gitolite, except how you need to add users and SSH keys through a git repository. I'd prefer just plain configuration files that I could manage with my configuration manager.

<comment><USER20> I've wasted so many hours trying to convince Windows user that they don't need any passwords for gitolite, they just need to check that Pageant is running and has the right key loaded :D

</comment></comment></comment><comment><USER21> Pretty sure both GitHub Enterprise and BitBucket Server are the dominant self- hosted Git solutions.

<comment><USER22> As mentioned in TFA, that was based on this source[1] which surveyed what "app developers" used. If you have alternative statistics, I'd be happy to see them, but GitLab did provide a source for their claim.

[1]: [http://blog.bitrise.io/2017/01/27/state-of-app- development-i...](http://blog.bitrise.io/2017/01/27/state-of-app-development- in-2016.html#self-hosted)

</comment></comment><comment><USER23> I really like Gitlab.

It allows you to organize your repos, and do things like nesting them in categories.

Why Github won't add this feature is beyond my understanding, and I really appreciate Gitlab stepping up and adding this into their platform.

They also have a great system for migrating your repos over from Github.

<comment><USER24> This! I'm at a small consulting shop (< 5 ppl), so it's really, really nice to have one subgroup per client; I'd hate having pages and pages of "client1-project1", "client1-project2", ... in a Github setup.

</comment></comment><comment><USER25> For some reason, different parts of the Gitlab CI software expect different names for the runner binary-- possible names are gitlab-ci-multi-runner and gitlab-runner.

If you set up a runner in a VM and want to upload artifacts, for some reason Gitlab CI requires you to install gitlab-ci-multi-runner on the VM guest (even though it is the host that is actually the runner). But when you do that, you have to actually go through the entire build process before seeing a non- terminal error that gitlab "couldn't find gitlab-runner". So now you have to go in on the VM guest, manually create a symlink from gitlab-ci-multi-runner to gitlab-runner, take a new snapshot of the VM state, and artifact upload will now work.

I say "non-terminal" above because a failure to upload the artifact doesn't fail the build. So you can be looking at all checkmarks for everything in your pipeline and have no idea for which of those jobs you actually got artifacts.

Also, every once in awhile I'll get failed builds where there is nothing at all in the build log. Typically, clicking "Retry" will successfully start a new build and complete successfully.

Also, there is no way to specify to gitlab to keep only the last N artifacts.

On the positive front, I finally figured out a way to set up an ssh server from _within_ the msys2 environment in Windows, which requires no development whatsoever on the gitlab-ci infrastructure. That means gitlab-ci will ssh into msys2 on the runner, giving me a POSIX-y build environment on all my platforms. So that's nice.

Sorry if this sounds overly negative and like a poor substitute for actually filing bugs. But the last time I worked on fixing a bug it took months for the maintainer just to click a button. This seems to be the only place I get timely response.

<comment><USER26> Thanks for your feedback, we're seriously considering all the input from the community, wherever it is coming from.

Talking about artifacts retention policy, we actually support defining an expiration date and we're also considering to add a maximum number in the future. You can find discussions about this topic in [https://gitlab.com/gitlab-org/gitlab- ce/issues/23777](https://gitlab.com/gitlab-org/gitlab-ce/issues/23777) and [https://gitlab.com/gitlab-org/gitlab- ce/issues/19208](https://gitlab.com/gitlab-org/gitlab-ce/issues/19208): in these issues there are also problems and consideration about having this feature implemented.

Feel free to jump in and push your ideas!

</comment></comment><comment><USER27> You know, this feature looks really cool, but the branding "Auto DevOps" seems like word-cloud clickbait and does not actually describe any distinguishing characteristics of the feature. DevOps is already a fuzzy area; what is Auto DevOps? It's at least another order of magnitude of semantic ambiguity.

<comment><USER28> The origin of "Auto DevOps" does seem to be a product branding creation:

[https://gitlab.com/gitlab-org/gitlab- ee/issues/2517](https://gitlab.com/gitlab-org/gitlab-ee/issues/2517)

<comment><USER27> That issue should have basically been in the press release; it's a lot clearer when they dump the branding and focus on actual concrete features they provide.

<comment><USER29> Thanks for the feedback. Maybe next time we talk about it, we'll be more clear about the features.

</comment></comment></comment></comment><comment><USER30> Gitlab is great. It took 5 minutes to install and has run flawlessly since.

I was blown away by how complete, fully featured, and easy to use it is for a free product.

<comment><USER29> That's great to hear; thanks for the feedback!

</comment></comment><comment><USER31> Huh, I thought gogs and its forks dominated self hosted git, because it's just so easy to set up and use.

</comment><comment><USER32> Does Gitlab have equivalent for Github Team account (5 users)?

<comment><USER33> We have free private repositories for all users and you can organize users into groups. Is this what you're looking for? If not, could you provide more context into what you're looking for?

</comment></comment><comment><USER34> I can no longer imagine using a CI system without job scripts committed. Could someone let me know why jenkins is still more popular?</comment>


Denied: Afghanistan's All-Girl Robotics Team Can't Get Visas to the US - <AUTHOR> https://www.forbes.com/sites/hilarybrueck/2017/06/29/denied-afghanistans-all-girl-robotics-team-cant-get-visas-to-the-u-s <comment><USER2> Educating girls is probably the single most effective way to bring about social change in repressive societies. Denying these girls visas is extremely short-sighted and counterproductive.

</comment><comment><USER3> America... what a nation of morons.</comment>


How I Would Design a Programming Degree - <AUTHOR> http://www.kodefuguru.com/post/2012/05/24/How-I-Would-Design-a-Programming-Degree.aspx

<comment><USER2> Completely disagree about excluding algorithms and data structures among other things. In fact, I would say current curriculums feature much too less of design skills in these departments.

Algorithms and Data Structures needn't be about existing ones, although they are great examples. Algorithm design skills are a prerequisite for getting anything done efficiently, quickly and readably. Design patterns and software development models are secondary.

The case of data structures being available in libraries will lead to confusion as students will lack the ability to select the one with most appropriate performance characteristics. To them the only difference will be syntax. You could argue that one can look up complexity characteristics, but then how can you teach someone what is complexity without doing algorithms and data structures?

Algorithms and data structures are so prevalent, that they drive design issues that on the surface seem unrelated. Why map reduce is the query format we are using; how Clojure can have immutable, persistent yet still fast data structures; why public key cryptography is safe? And more importantly, algorithms and data structures teach us about tradeoffs.

It's not by accident that top companies test algorithm skills in interviews.

</comment><comment><USER3> This is not radically different from most (ABET accredited) undergrad CS degrees.

Intro programming sequence: \- Critical Thinking \- Logic \- Imperative Programming \- Object-oriented Programming

Databases: \- Relational Data \- Object-relational Mapping

Technical communication & ethics: \- Professional Communication \- Professional Conduct

Software engineering sequence: \- Human-readable Data (also in databases) \- Refactoring \- Object-oriented Design Patterns \- Requirements and Specifications \- Organizing

Software testing (elective): \- Unit Testing

Senior design projects: \- Develop Software

Misc:

\- Declarative Programming --> We learn regex in an intro to Linux course, XML in software engineering, etc.

\- Tools of the Trade --> Picked up on your own, from profs, TAs, teammates, etc.

Which leaves only the following courses unaccounted for:

\- Optimizing --> General optimization strategies aren't really taught at my university without looking for specific elective courses.

\- User Interface Design --> Sadly, CS does not seem to concern itself much with the front-end of software; I wish this were not the case.

</comment><comment><USER4> That's pretty much what my CS undergrad was about (european university).

In addition to everything mentioned by the author, we also had algorithm design, a lot of math (analysis, linear algebra, probabilities, statistics, topology, graph theory from the top of my head), economics, law fundamentals + intellectual property law, project management, communication + marketing, economics, english as a second language, and electives in our final years (computer graphics, etc.).

</comment><comment><USER5> This seems sensible. Of course many people could quibble about things they wish were included or dropped, but almost all of this stuff I've had to learn the hard way. Having most of this information presented to someone in an organized way would go a long way towards making them a formidable hire.

</comment><comment><USER6> What about functional programming? I quite liked my class on it. Also, at my school, we have a course on realtime programming on embedded systems. It's a cool class, I would like to still see it around. Also, a class on bash and unix would be good.

<comment><USER2> Functional programming falls within the realm of declarative programming, so he's got that covered actually.

</comment></comment><comment><USER7> Courses in organizing and tools of the trade but no data structures?

</comment><comment><USER8> no formal study of the analysis and design of algorithms?

<comment><USER9> See the section titled "On the Glaring Omission."

<comment><USER10> From my perspective, the point of a Data Structures class is not so that students can implement a red-black tree or skip-list off the top of their head- it's so that the performance characteristics of those structures and their associated algorithms will be deeply engrained. I've never needed to implement a hashmap from scratch in industrial code, but I've sure as hell needed to understand how they work beyond simply memorizing "insertions and lookups approach constant time". Algorithms is a similar story. I think leaving those courses out of a programming curriculum will result in mediocre programmers at best.

</comment></comment></comment><comment><USER11> I would add the course: "Reading Code."</comment>


"Whom" is disappearing and everyone needs to chill about it - <AUTHOR> https://qz.com/1517643/should-we-let-the-word-whom-die/ <comment><USER2> Do you want to read _For Who the Bell Tolls_? Neither do I!

<comment><USER3> Then it's a good thing Hemingway didn't write it.

English changes: the rest of that John Donne sentence is "the bell tolls for thee"? Should we bring back "thee" and "thou" as pronouns? I'm guessing yes, but then we have to decide if "thee" has informal/personal connotations as per originally, or if "thee" is now formal, as we've come to view it in these latter days.

Ditch "whom". Using it makes you sound like an Ent,</comment></comment>


Ask HN: How common are hybrid iOS Android developers? (mid-level) - <AUTHOR>

<comment><USER2> I was also thinking about the same thing. I think there are similar concerns while developing for both the platforms and if there is one person who is working on both there will be much better reuse of concepts and functionality. From maintenance point of view also it might be better if one person can do both. I am not sure if big companies will prefer to have hybrid developers but smaller companies will definitely appreciate the savings and speed-up such hybrid developers could bring.

<comment><AUTHOR> Pretty good point, actually - distinction between the small and large companies.

To date though, I only met two people who are proficient in both, and do it day to day.

<comment><USER2> I have been moving in the same direction. Trying to get proficient with both the platforms. I have got background in both Java and C++ so that makes it slightly easier. At this moment, I am trying to explore if there is some kind of "economies of scale" in learning both the platforms.

</comment></comment></comment><comment><AUTHOR> If you're an employer, is this a desirable trait, or would you want just one stellar person per each platform?

<comment><USER3> For my company, mobile apps aren't expected for our service but we want to create them for a better user experience. So we would likely be fine settling for a mid-tier person who can do both over top-tier people who are specialized.</comment></comment>


"Codeless" back end with postgREST - <AUTHOR> https://www.mathieupassenaud.fr/codeless_backend/ <comment><AUTHOR> here it is : [https://github.com/mathieupassenaud/codeless- backend](https://github.com/mathieupassenaud/codeless-backend) have fun :)

<comment><USER2> You can submit this link as a PR to this page [https://github.com/PostgREST/postgrest- docs/blob/v6.0/ecosys...](https://github.com/PostgREST/postgrest- docs/blob/v6.0/ecosystem.rst)

</comment></comment><comment><USER2> is there a github repo with all this sample code?

<comment><AUTHOR> not right now, in a few hours :)</comment></comment>


Ron Paul fears NSA leaker assassination - <AUTHOR> http://www.cbsnews.com/8301-250_162-57588886/ron-paul-fears-nsa-leaker-assassination/

<comment><USER2> It sounds from the tone of the statement that Ron Paul was exaggerating to make a point. The title is sensationalist.

</comment><comment><USER3> An MD who is in it for the right reason is hacker; I think Ron and Rand are hackers.

</comment><comment><USER4> lol, the only thing Ron Paul is concerned about is being forgotten...</comment>


Ask HN: Shouldn't AI be more correctly called just efficient optimization? - <AUTHOR> Every time I talk about AI in public I get the "But is it really Intelligence?" question, and the whole thing devolves into stupid semantic flaming. Shouldn't we really just drop the whole "AI" flag and just call what's done now something non-controversial, like data-driven non-linear optimization, or something? <comment><USER2> I would say "no". AI is a HUGE field with a long history and many, many many sub-disciplines and elements. If you want to argue for renaming "deep learning" to "data-driven non-linear optimization" then you might have a point, but "deep learning" is just a small subset of "AI" as a whole.</comment>


Why You Shouldn't Walk on Escalators - <AUTHOR> https://mobile.nytimes.com/2017/04/04/us/escalators-standing-or-walking.html?referer=https://www.google.com/url?sa=t&rct=j&source=web&q=&url=https://www.nytimes.com/2017/04/04/us/escalators-standing-or-walking.html <comment><USER2> "It's more efficient if everyone stands on an escalator instead of some people walking on it,"

surely it would be even more efficient if everybody walked on escalators

<comment><USER3> no because walking takes up more space per person, dropping throughput.

</comment></comment><comment><USER4> The argument is that it's safer to stand side by side. But people probably walk for speed, not safety. So unless they make it a rule and enforce it, I don't see people changing habits.

<comment><USER3> that's not the argument at all- it's not safety, but total throughput. The speed argument makes only a bit of sense- a few people attain higher speed, but at dramatically lower total overall throughput.</comment></comment>


Google Trends Visualizer - <AUTHOR> http://www.google.com/trends/hottrends/visualize

<comment><USER2> Cool! But as useful as a lava lamp.</comment>


Ask HN: Most convincing evidence that a US economic recession is coming in 2020? - <AUTHOR> <comment><USER2> One is unlikely to outthink Bloomgberg's recession index, especially since recessions are usually the result of collective loss of confidence: [https://www.bloomberg.com/graphics/us-economic-recession- tra...](https://www.bloomberg.com/graphics/us-economic-recession-tracker/)

</comment><comment><USER3> A recession will come, but who knows if it will be in 2020.

There are plenty of things to be concerned about, such as [0], but the existence of explosives does not imply an explosion is imminent. There needs to be a spark in the right place. Tectonic plates interacting means there will be seismic activity, but when and of what magnitude? Such questions are impossible to answer with any detail and certainty.

[0] [https://www.zerohedge.com/markets/different-acronyms-same- di...](https://www.zerohedge.com/markets/different-acronyms-same-disaster- bond-ratings-are-once-again-sale)</comment>


The lights are going out all over Twitter - <AUTHOR> http://www.guardian.co.uk/technology/2009/feb/17/internet-newzealand <comment><USER2> I'm getting sick of the "vote this up if you want ___" mentality. If you want to change the world, start by understanding it well enough to know that you need to convince people outside new media.

</comment><comment><USER3> I can appreciate the sentiment behind this, but how in the world is this going to change anyone's mind? Do the decision makers in New Zealand even know what Twitter is?

<comment><USER4> I think the purpose of these plans are to raise awareness in the mainstream media. This article is a good example of this tactic working. It doesn't matter if the decidion makers know what Twitter is, they know what newspapers are.

In Canada when the government introduced their new copyright laws about 100,000 people joined a facebook group overnight. Alone that group wouldn't achieve much, but all media picked up the "100,000 people Facebook group" and it was headlines for days, causing the government to backdown on the bill.

I do agree that if people want to change the world they should get out and do something to change it directly, but if they aren't willing to do that these small online protests still do affect the real world.

</comment></comment><comment><USER5> Ideas are waves and the Internet is just a medium.</comment>


The Speed of a Unicorn - <AUTHOR> https://fleximize.com/unicorns/ <comment><USER2> This list is quite confusing.

What defines "start-up"?

Take go-pro, they're a product company that had huge success with a hit product. They successfully re-invested to keep that product business successful and the business grew to 1bn.

Does unicorn just mean non-publically traded company worth > 1bn?

<comment><USER3> This.

How is it that Avast is still a "startup" when it was founded in 1988?

I mean.. they were founded even before the dot com bubble!

Edit: I know there's always a problem when trying to define what is and isn't a startup...but by all metrics I could think, Avast isn't one of them. I mean, otherwise we would also need to include the likes of Microsoft, Oracle, Google, Amazon as other unicorn startups, no?

<comment><USER4> A unicorn is a company that has reached 1bn valuation while staying private. So Microsoft, Oracle, Google and Amazon don't qualify (while Google definitely was one for some time, it's just that the term didn't exist back then). Of course it also puts PwC and Bechtel in this league...

</comment></comment></comment><comment><USER5> Crazy thought: If there's so many billion dollar startups now, maybe we shouldn't be referring to them as Unicorns anymore? Taking a term that was used to refer to exceptional businesses and proliferating the use of it makes me even more weary of VC-run companies than I already am.

<comment><USER6> We need something for the > $10 billion club. Hippogriffs?

<comment><USER7> decacorn.

</comment></comment></comment><comment><USER8> Does anyone know anybody who has ever ordered something from jet.com? No one I've asked has ever heard of it, and they did an enormous media blitz in Boston.

<comment><USER9> I ordered something from jet.com, was a terrible experience, would not recommend. They apparently decided that my order was fraudulent, cancelled my order, locked my account, _did not tell me and continued to send me marketing spam_. I only found out when I emailed them a few weeks later to ask "what gives?"

</comment></comment><comment><USER10> It would be nice to see the same graph from parallel universes, to determine which of these companies became unicorns by mere luck.

<comment><USER11> Luck is necessary, but not sufficient condition for becoming a successful company.

</comment></comment><comment><USER12> It's quite scary to see so many names I've never even heard about before, and then to see some names that clearly make no sense also there.

Let's face it, for instance, Avast? Seriously who came up with that insane valuation for a company like Avast?

<comment><USER13> AFAIK Avast is betting on monetizing anti-virus usage data.

I wonder why Mojang is not on the list, though.

<comment><USER14> Either "Games aren't real software", "If it's not in the US, we mostly don't care" or "Real Unicorns take VC and get acquired by Facebook, Microsoft acquisitions don't count".

Pick your poison.

<comment><USER15> Garena is on the list, and they are in the gaming industry.

</comment></comment></comment></comment><comment><USER16> Does nobody seem bothered by the fact that "valuation" is usually bulshytt?

<comment><USER17> fab.com (included in the list as once having a 1B valuation) was sold in a $15M fire sale [1], which does make one wonder..

[1] [http://qz.com/300825/how-fab-com-went-from-a-1-billion- valua...](http://qz.com/300825/how-fab-com-went-from-a-1-billion-valuation- to-a-15-million-fire-sale/)

</comment></comment><comment><USER18> Prior to an IPO or acquisition, valuations have approximately the precision and accuracy of agile estimates chosen from a drop-down list populated with values from an echo chamber inhabited by....

</comment><comment><USER19> At first I thought these were page load times until I read the description.

On topicL I am not from the US, and I've never hear of Jet, but so have none of 8 randomly selectedfriends from the US.

</comment><comment><USER20> Very nice work but it seems like some companies are not in the right category. Like Zenefits is in Fintech category.

</comment><comment><USER21> Building a business is hard. Really respect the achievement of these companies.</comment>


Ask HN: Message Queue use cases - <AUTHOR>

Are you using a message queue? Perhaps you are using something like AMQP to keep your various applications together? What sort of uses are you putting your message queue to? <comment><USER2> I use MQ's to queue things that I want to do that are computationally expensive but shouldn't impact the user experience. A feature that is necessary but doesn't require immediate execution. For example, I use a MQ to manage the creation of thumbnails on a website that I manage when somebody uploads a new photo.

</comment><comment><USER3> Use it to schedule "near time" jobs that are not suitable to do inline during a web request.

</comment><comment><AUTHOR> Ok...I will go first ;)

One of our clients is using a MQ to link a fleet of 550 electric vehicles to a head office app that checks for vehicle service issues.

</comment><comment> adam-_- Synchronising product/stock details from warehouse to website.

</comment><comment><USER4> You should rename this to "Ask HN".</comment>


Mathematica on Raspberry Pi for free - <AUTHOR> http://www.raspberrypi.org/archives/5282 <comment><USER2> Timeo Danaos et dona ferentes... I fear the Greeks even when they bring gifts...

I don't get it... Wolfram is a money-hungry egomaniac. For example, unlike the other big Ma competitors (Maple, Matlab, Magma) not a single source line of Mathematica code is exposed. He's litigious, he labels everthing "mine", he endlessly praises himself. He wrote this insulting "don't worry your pretty little head with our source code, it's too complicated for you" piece:

[http://reference.wolfram.com/mathematica/tutorial/WhyYouDoNo...](http://reference.wolfram.com/mathematica/tutorial/WhyYouDoNotUsuallyNeedToKnowAboutInternals.html)

So... gratis Mathematica on Raspbian... what's the catch? Is it to lure us to the cloud?

[http://www.wolframcloud.com/](http://www.wolframcloud.com/)

Edit: To clarify, my guess here is that they want to give people a taste of Mathematica on weak hardware in order to lure them to a subscription model on "the cloud" where much more processing power will be available, just like widespread university site-wide licenses and turning a blind eye to student piracy are great marketing strategies.

Is there any evidence to support my wild theories?

<comment><USER3> What a ridiculous post. The quote in question is a reference the Trojan horse, so unless you are suggesting that loading Mathematica onto the Pi will, in fact, destroy it, I don't see any merit to this analogy. And while it's true that Steve Wolfram is incredibly arrogant, so too is the act of publicly shaming him for refusing to share his code, no? The man has spent the last 25 years perfecting his product and along comes you, acting like you have some God-given right to inspect its inner workings. Gimme a break.

<comment><USER4> > along comes you, acting like you have some God-given right to inspect its > internals

Well,it's mathematics software, so it's actually really not unreasonable. Fortunately, the rest of mathematics has moved past the seventeenth-century style of "Here's my result, the proof is secret". If Mathematica is intended to be suitable for mathematical research, then its source must be open so that the results are auditable.

Other mathematics software like Sage doesn't have this problem, and is already available for the Raspberry Pi for free, obviating the need to use Mathematica.

<comment><USER5> > If Mathematica is intended to be suitable for mathematical research, then > its source must be open so that the results are auditable

You don't need source to audit the results. It's a tool, just like a calculator or a table of logarithms or a table of integrals. If I use an HP calculator for a calculation, for instance, you don't audit my results by examining the source for the calculator's firmware and convincing yourself it is right and then accepting my results. No, you audit my results by doing the calculation on your Casio calculator and seeing if it comes out the same.

<comment><USER6> > You don't need source to audit the results.

In fact, you do. Modern computer mathematical results require full exposure, nothing can be left to the imagination. This is true and understandable.

Going back to the first important computer mathematical result (the solution to the four-color map conjecture¹ in 1976), to be taken seriously, computer math results have been required to be fully transparent.

Imagine auditing a cancer cure without knowing anything about the methods or tools. Same idea.

1\. [http://en.wikipedia.org/wiki/Four_color_theorem](http://en.wikipedia.org/wiki/Four_color_theorem)

<comment><USER7> I actually somewhat sympathize with your view. But I think you overstate the problem: if someone discovers something with Mathematica, they can then formalize it with an open proof assistant like Coq before they publish, and modern journals in fact encourage this sort of thing.

Really, it's not a zero-sum-game between open-source and commercial tools.

<comment><USER2> "Open source" and "commercial" are not antonyms, but people working on proprietary software think they are.

<comment><USER8> Only if you use an overly literal interpretation of "commercial" yet don't use the literal interpretation of "open source" (since it's also possible to make source code visible to the public without using a license that would be considered "open source").

<comment><USER9> You have just rediscovered the reason that some people talk about "free software", and some people talk about "open source".

The sort of access to source code that is being expected here is really no more than the sort of access that you can get to Windows code. It _really_ is not an unreasonable expectation.

<comment><USER8> No - when most people use the term "open source", they mean something along the lines of the Open Source Definition ([http://opensource.org/definition](http://opensource.org/definition)), rather than the literal meaning; this is independent from the distinctions between open source and free software, which are mostly about philosophy rather than the set of applicable licenses ([http://www.gnu.org/philosophy/free-software- for-freedom.html](http://www.gnu.org/philosophy/free-software-for- freedom.html))

I suppose that you, however, do not, which makes what I was trying to say irrelevant.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER10> This is why Debian does _not_ recommend Raspberry Pi [0]

> Despite the hype it is a more closed platform than many other things you > could buy

Claiming to be open, but still encouraging and endorsing non-open-source software. I was startled to read why R.Pi is unsuitable for education [1]

[0]: [https://wiki.debian.org/RaspberryPi](https://wiki.debian.org/RaspberryPi)

[1]: [http://whitequark.org/blog/2012/09/25/why-raspberry-pi-is- un...](http://whitequark.org/blog/2012/09/25/why-raspberry-pi-is-unsuitable- for-education/)

<comment><USER11> Given that most educational uses of the Pi won't involved developing things at such a low level as to require detailed specs of the processor and that the OS's for the Pi are all freely available that article would probably be better titled "Why the Pi is unsuitable for educating hardware engineers about ARM."

The $25 price point is more important to the educational use (K-12) then any specs put out about the hardware. I don't need to know any of that to learn Python for instance.

<comment><USER12> That's a very patronizing attitude. There are a good number of high school students that are already at the level of reverse engineering drivers.

<comment><USER13> Yes, and the Raspberry Pi is not designed for them. There is no reason it should cater to _everyone_ , it's designed for those who _aren 't_ experienced with programming, hacking and reverse engineering so they can start on their learning experience without a large financial barrier to entry.

<comment><USER12> You're missing my point, which is that high school students are _capable_ of this kind of thing, and it would be perfectly possible to push yet more of them along that route given the right environment and attitude.

</comment></comment></comment></comment></comment><comment><USER14> Kudos to Wolfram for this.

I do wonder how much pressure they're feeling from the likes of IPython these days and if that was a motivating factor.

The other part is I don't think I've met a regular Mathematica user that actually likes it, so this may turn out to be a bad idea!

<comment><USER15> IPython is great system for interactive programming, especially for someone who is familiar with Python and is able to find a complete distribution or able to set up all the details about their distribution (e.g. avoid problems like [https://news.ycombinator.com/item?id=6725597](https://news.ycombinator.com/item?id=6725597)), or someone who requires free-as-in-speech software.

I don't use either IPython or Mathematica much, but I would understand preferring Mathematica over IPython given the choice. Aside from being younger, IPython is made of a combination of systems without a strong conceptual glue tying them together. Mathematica is made of a combination of systems too (kernel written in C, various external libraries in C, Lucene search engine, etc), but the components are tied together using what I guess is now called the Wolfram language, where everything, from computations to settings to notebooks themselves, is specified in Wolfram language expressions. If you view an IPython file in a text editor you see JSON, which is different than the language used to compute. If you open a Mathematica notebook in a text editor you see a nested set of Wolfram language expressions. Mathematica grew up around that idea.

As a further small example, compare the prompts to the two systems:

      IPython
      In [1]: 1+2
      Out[1]: 3

vs

      Mathematica
      In[1]:= 1+2
      Out[1]= 3

In IPython, the array brackets are just a sort of notation--the assignment isn't syntactially correct Python. But in Mathematica, you can view that prompt as assigning the value of an In list at index 1 the expression "1+2".

That sort of consistency holds through the entire system in a way that IPython can't match.

<comment><USER16> I am not sure if you are aware of this, but you can access the history of IPython inputs and outputs through the two arrays `In` and `Out`. This prompt is precisely indicating this.

<comment><USER15> Thank you for pointing that out. I meant to show that while they both store their inputs and outputs in array-like structures, Mathematica does it in a way that is valid in its own syntax, and IPython does not.

In Mathematica "In[1]:= 1+2" is a syntactially valid expression (though the literal In symbol is protected), so you could do the following:

      In[1]:= in[1]:= 1+2

and the interpreter would evaluate it (though the values of In[1] and in[1] would be different).

But even with all of the symbols defined, this is not valid Python (according to [https://www.pythonanywhere.com/try- ipython/](https://www.pythonanywhere.com/try-ipython/)):

      In [1]: in=[]

      In [2]: in[0]:1+2
        File "<ipython-input-2-b9cd4c9ee15d>", line 1
          in[0]:1+2
               ^
      SyntaxError: invalid syntax

The fact that this trivial expression is valid in Mathematica and not in IPython by itself says nothing about the relative merits of each system. IPython could be modified to use another notation for the input/output arrays, and Mathematica would work just as well if it were changed to use some syntactically incorrect notation. But what I was attempting to show is an example of how consistent Mathematica is.

</comment></comment></comment></comment><comment><USER17> You can read Wolfram's post about it here. [http://blog.wolfram.com/2013/11/21/putting-the-wolfram- langu...](http://blog.wolfram.com/2013/11/21/putting-the-wolfram-language-and- mathematica-on-every-raspberry-pi/)

Note that it includes a beta version of the new Wolfram Language!

</comment><comment><USER15> You know who else bundled Mathematica for free?

[http://en.wikipedia.org/wiki/NeXT#Software_applications](http://en.wikipedia.org/wiki/NeXT#Software_applications)

</comment><comment><USER18> So all I need for a free mathematica install is to spin a virtual machine with Raspbian?

<comment><USER19> I would imagine you'd need an ARM-based virtual machine. Perhaps QEMU could do it.

<comment><USER19> That said, it sounds like it might be a hassle to get that to work on a Mac.

I got the personal license of Mathematica for Mac a while ago and thought the price was reasonable for such a powerful system.

The only thing that was driving me nuts is that Mathematica does not work properly on a Retina display, which of course is a shame as text and graphics would look gorgeous. Support for that is only planned for the next major version, according to Wolfram ([http://mathematica.stackexchange.com/a/30104/10565](http://mathematica.stackexchange.com/a/30104/10565)).

I recently found a hacky fix: [http://mathematica.stackexchange.com/a/21158/10565](http://mathematica.stackexchange.com/a/21158/10565)

With that, Mathematica now looks fantastic on my MacBook Pro's built-in screen.

<comment><USER7> V10 is retina aware, and it's coming out soon.

<comment><USER19> Given how easy the quick fix is to apply, basic Retina support should really have been in a free minor-version update to 9, not in a presumably paid upgrade to 10, after a long wait.

<comment><USER7> I believe it required getting rid of some legacy libraries, which couldn't be achieved in a point release.

</comment></comment></comment></comment></comment></comment><comment><USER20> [http://www.reddit.com/r/lisp/comments/1mmm02/screenshot_of_f...](http://www.reddit.com/r/lisp/comments/1mmm02/screenshot_of_fricasaxiom_running_on_my_tiny/)

FriCAS/Axiom running on ARM board (ie. Raspberry Pi) on top of Clozure CL (on Ubuntu/GNU/Linux)

</comment><comment><USER21> It has been my hope for many years that Wolfram would open-source Mathematica one day. I can think of no better way to ensure his legacy.

</comment><comment><USER13> seems like buying a Raspberry Pi just became an extremely cheap way to get Mathematica, then.

<comment><USER22> Yes, for non-CPU-intensive applications.

<comment><USER23> I'd run an ARM emulator on top of a x86 stack, but the R-Pi is not just an ARM machine..

</comment></comment></comment><comment><USER24> So how many Pis can you cluster together to equal the performance of a standard i3/5/7 laptop (for non-GPU bound calculations)?

<comment><USER18> That'd be a fun experiment. If only I had disposable income :).

I wonder how much heat these things produce? Could they be used to make an efficient, small cluster?

<comment><USER25> You could make a cluster with them (in fact for none-mathematica uses it has been done).

Efficient not even remotely the performance per unit of a Raspberry Pi just makes it not worth it (note: it's worth it if you want to simulate multi-node programming, SMPP type stuff).

For example a 32 node raspberry pi machine clocked 10.9Gflops on linpack[1], 32 * 35 is $1120 (excluding switches, cabling, power supplies which would add at least another $200 or so).

A _single_ Nvidia Titan clocks ~1.5 _Teraflops_ in double precession mode for ~$1000 (a performance per dollar rate of 137 times _better_ ).

According to wikipedia[2] a cheap Sempron 145 with 3 Geforce GTX760's at $1090 has a performance of 6.771 teraflops (so over 500 times the performance of the 32 node raspbery pi)

1 [http://www.zdnet.com/build-your-own-supercomputer-out-of- ras...](http://www.zdnet.com/build-your-own-supercomputer-out-of-raspberry-pi- boards-7000015831/)

2 [http://en.wikipedia.org/wiki/FLOPS](http://en.wikipedia.org/wiki/FLOPS)

</comment></comment></comment><comment><USER26> Cool, but I've been using python+scipy+sympy on a pi for almost a year now. I think Wolfram is a bit behind the curve.

<comment><USER27> I'm curious, what are you using it for?

</comment></comment><comment><USER28> Does anybody know what license this is released under? For example, can one run it under an emulator? On something more powerful than a Pi? Using an ARM- to-my-CPU jitter (does that work at all, or does Mathematica have its own JIT inboard?)

If one managed to hack the binaries and include them in an iOS app, would Wolfram permit that?

<comment><USER17> "...free for anyone to use for personal purposes. (There's also going to be a licensing mechanism for commercial uses, other Linux ARM systems, and so on.)"

[http://blog.wolfram.com/2013/11/21/putting-the-wolfram- langu...](http://blog.wolfram.com/2013/11/21/putting-the-wolfram-language-and- mathematica-on-every-raspberry-pi/)

<comment><USER28> Thanks. I think the "on the Raspberry Pi" part of the statement in that post is significant, though. I doubt they will feel fine if someone wrote a clone of the Mathematica kernel and copied over the notebooks from this release, to be run on, say, a desktop PC.

</comment></comment></comment><comment><USER29> Try out an emulation and see if you like it. Here is one on OS X.

[http://maxvitek.wordpress.com/2013/11/24/get-mathematica- on-...](http://maxvitek.wordpress.com/2013/11/24/get-mathematica-on-your- emulated-raspberry-pi/)

I find that it's fine for most things but slow for visualizations (and you need an x server running, not making the most of the emulated hardware).

(Can anyone succeed in using this method and then adding it as a remote kernel to a normal desktop Mathematica session?)

</comment><comment><USER27> Mathematica being what it is, what are science intensive problems worth solving on raspberry pi without uploading to a server? I'm thinking along the lines of robototechnics. Something like calculating a ballistic trajectory for autonomous gun turret with statistical analysis of precision via feedback loop. Feedback being the delay of sound of projectile impact for impact distance. Or visual position of a hit. You get the idea. What can you think of for civil use?

<comment><USER30> Given the focus of RPi on teaching school age kids programming, maths homework.

</comment></comment><comment><USER31> ARMv6 doesn't support hard float, right? Why would you want to do calculations on an Pi?

<comment><USER32> Mathematica can deal with arbitrary-precision numbers (or better said, Mathematica doesn't blindly use whatever underlying number format is present, it has precise controls for this sort of thing [http://reference.wolfram.com/mathematica/tutorial/ArbitraryP...](http://reference.wolfram.com/mathematica/tutorial/ArbitraryPrecisionNumbers.html))

</comment></comment><comment><USER33> Interesting marketing strategy: free is good advertising, but (FWIU) the raspi doesn't have the horsepower to compete with Wolfram's actual products.

</comment><comment><USER34> Wasn't Raspberry Pi supposed to be free software?

<comment><USER2> No. That's just marketing hype.

[https://wiki.debian.org/RaspberryPi](https://wiki.debian.org/RaspberryPi)

</comment></comment><comment><USER35> Does it mean a 600MB package on the Raspbian image?</comment>


Ask HN: What is the optimum length of an explainer video? - <AUTHOR>

I am working on a script for an explainer video for my product http://www.skillendar.com. To make it funny and more interesting I have to add some unrelated content which in turn is increasing the length of the video to about 3 minutes. Do you think I should restrict the length to 90 seconds in order to retain the viewer's attention? This would mean that I would need to compromise on the whole story line. <comment><USER3> Clickety ... <http://www.skillendar.com>

I speak from zero experience of selling, but a great deal of experience of public speaking ...

What really, really matters is seeing something interesting early. Really early. First 3 seconds maximum. And not generically interesting - <USER2> specifically to a person who will give you money.

If they won't give you money, you don't care.

So who will give you money? Figure out who they are, and make sure they see something they want within 3 seconds.

Beter yet - 1 second. Hard to achieve. Be creative.

<comment><AUTHOR> Yes, that makes sense; difficult to achieve though

<comment><USER3> Indeed, it's something like the "Boil the Oceans" solution.

But to some extent, that's the point. I've outlined a suggestion for what you're trying to achieve at the next level down. It's now your job to think creatively to find a way to do it (assuming you think it's right).

If you succeed then you're doing better than your competitors, for I've rarely seen it done at all.

</comment></comment></comment><comment><USER4> As short as possible. If it takes more than 5 seconds to start seeing the product, I'll start skipping around or leave the site. You don't need a title sequence or intro music. Just start. Get to the point. Make the point. Then stop.

Also, assume some viewers will have their sound muted. Assume some others will switch to another tab and only listen to it.

<comment><AUTHOR> That's a very good point. I will take that on board. Thanks

</comment></comment><comment><USER5> I don't believe their is a specific length, obviously if it is too long, unless it is very interesting most people will click away. However this is really besides the point, I believe if your service meets a potential customer's needs, the length of your video isn't going to matter. Someone can click away from a long explainer video and go straight to the product if it is useful to them. All these gimmicks about conversion are just that, gimmicks. If your product meets customer's needs, you'll make the sale.

</comment><comment><USER6> While this data is not specific to "explainer" videos, it is data compiled over the viewing of business videos.

<http://wistia.com/blog/does-length-matter-it-does-for-video/>

Bottom line, keep it as short and as punchy as possible.

</comment><comment><USER7> 3 minutes is very, very long. I'd shoot for 1 minute. As RiderOfGiraffes said, catch the attention in the first few seconds.

As in writing, editing is king. Remove bits.</comment>


Megacoin: A new global currency - <AUTHOR> http://www.megacoin.co.nz/

<comment><USER2> A scammy cut-n-paste altcoin that tries to cash in on an implied but non- existent relationship with Kim Dotcom.

Stop ruining HN with crap posts like this.

<comment><USER3> Please note that it would actually be worse if they had a connection with Kim Dotcom. To accurately judge his character, you cannot rely on the descriptions of his exploits as international "Mega-man".

His english language Wikipedia article has been largely cleansed of what he did in Germany and his German article also just glances over what happened[1].

That guy stole and sold credit card info and ratted out fellow internet citizens for (I kid you not) illegally sharing copyrighted material. Do not trust.

[1] [http://translate.google.com/translate?sl=de&tl=en&js=n&prev=...](http://translate.google.com/translate?sl=de&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fde.wikipedia.org%2Fwiki%2FKim_Schmitz%23Werdegang)

</comment></comment><comment><USER4> > Yes! Of course! August 28, 2013! That was the day I invented time-dilated > difficulty gravitational wells. The black holes of difficulty formulas! I > remember it vividly. I was standing on the edge of my toilet about to upload > a standard fork, the porcelain was wet, I slipped, hit my head on the sink, > and when I came to I had a revelation! A vision! A picture in my head! A > picture of this! [1] This is what makes time-dilated difficulty formulas > possible: the Kimoto Gravity Well! It's taken me nearly sixty six years and > my entire family fortune to realize the vision of that day. KGW = 1 + > (0.7084 * pow((double(PastBlocksMass)/double(144)), -1.228)); Marty, we > don't have much time, we must release it upon the universe today. The future > of Megacoin depends on it.

After a few minutes of browsing their Github and about page it looks like it is based on this forum post [2]. edit: After further investigation it looks like it uses MurmurHash3 and scrypt... but it's definitely less interesting than Dogecoin.

1\. [http://i1367.photobucket.com/albums/r783/megacoin/KimotoGrav...](http://i1367.photobucket.com/albums/r783/megacoin/KimotoGravityWell_zpsa1364d62.png)

2\. [https://bitcointalk.org/index.php?topic=240861.msg3040291#ms...](https://bitcointalk.org/index.php?topic=240861.msg3040291#msg3040291)

<comment><USER5> Just to clarify for anyone who isn't sure: Yes, it is all bullshit.

</comment></comment><comment><USER5> How is this different from any other scammy altcoin? I don't get it.

<comment><USER6> cuz, it's got animations!

<comment><USER5> So it is starting to look like the pump and dump schemes now have money behind them.

</comment></comment></comment><comment><USER7> Looks like an alternative Litecoin blockchain:

[http://cryptolife.net/in-depth-altcoin-analysis- megacoin/](http://cryptolife.net/in-depth-altcoin-analysis-megacoin/)

Nothing particularly interesting.

<comment><USER8> The reported stealth launch is interesting, if depressing. Stealth launches are essentially a deniable form of premine and not a good indicator for a coin's future, historically. I know I won't be trading this coin or recommending its markets.

</comment></comment><comment><USER9> I'm guessing it's intentionally using the "mega" prefix and a New Zealand domain to conflate itself with Kim dotcom's ventures? How is this not a scam?

</comment><comment><USER10> Bear in mind this has nothing to do with Kim Dotcom. It's just another Litecoin fork ripping off the Mega trademark and branding.

</comment><comment><USER11> Oh, another scrypt based altcoin. that's refreshing.

<comment><USER12> But this time they're mooching off Kim Dotcom's branding.

<comment><USER13> Is there any confirmation Kim Dotcom isn't behind it? This seems like the kind of hustle that's right up his alley.

</comment></comment></comment><comment><USER14> Just a note, this site literally crashed my iPhone.</comment>


End Wall Street's Stranglehold on Our Economy – Elizabeth Warren - <AUTHOR> https://medium.com/@teamwarren/end-wall-streets-stranglehold-on-our-economy-70cf038bac76 <comment><USER2> Peter Thiel thinks she's dangerous, which sounds like an endorsement to me!</comment>