BBC Click: How to Set Up a VPN at Home Using a Raspberry Pi - <AUTHOR> http://www.bbc.co.uk/news/technology-33548728

<comment><USER2> I've found this script to be a huge timesaver when setting up an OpenVPN server:

[https://raw.githubusercontent.com/Nyr/openvpn- install/master...](https://raw.githubusercontent.com/Nyr/openvpn- install/master/openvpn-install.sh)

I can also confirm it works just fine on the Raspberry Pi.

</comment><comment><USER3> It'd be nice if those sort of thing became common enough that the BBC had get some syntax highlighting/code formatting set up.

Not that the BBC is some monolithic entity, but it's still interesting that they chose to publish this. No doubt some would consider it a political statement.

</comment><comment><USER4> I have a set of scripts that I've compacted into a one-click binary that spin up new AWS instances as a VPN. Would people buy this? (I'm planning on a Show HN: in a week or two, once I get the final debugging and product artwork done.) Even then, I'm really not sure if there is an advantage in having you're own home-grown VPN or using a service like StrongVPN (or any of the other "google: private vpn service" VPN service providers)?

I'd like to think that people would want to "run" their own, but I'm wondering if most even would care.

<comment><USER5> I would not be a client.

An AWS is about US 10 per month ? So that is rather expensive compared to the online services. The online services have you choose very easily between different countries. A bit more difficult / limited with AWS ?

Will the 'login' ip address always stay the same in your setup ? (I mean in case I stop the remote machine and later start it again).

On the upside: AWS is probably more secure (no man in the middle possible) and maybe faster ?

First you should make a good description of those 'people' who want to run their own vpn. What are their reasons.

<comment><USER4> Thanks for the suggestion on the description. That should help in preventing me from conflating the different use-cases of running a VPN. For example: viewing a US Netflix account while in India vs. At public coffee shop vs. Protect myself and my family from persecution.

The login would change as you bring up and down servers. You get a new fresh install of the service on an instance each time you start a new one up. (Although the option to start and stop could be easily implemented.)

You can choose between all of the AWS Cities/Countries that AWS offers which is 9 across Asia, Australia, Europe, The USA and South America. Which hopefully would provide a good mix for a while.

As for expense, this is where the different use cases come in. If you want to secure a coffeeshop connection for a few hours then you'd just pay a few cents for the protection, which I think is reasonable. But if you want a more permanent connection then I may need to think more about the costs, or starting and stoping servers automagically to save costs.

</comment></comment></comment><comment><USER6> cool

... but ifconfig and nano ... really?

:P</comment>


Dennis Ritchie: "So fsck was originally called something else" - <AUTHOR> https://groups.google.com/forum/#!msg/alt.sysadmin.recovery/tsGbbkvHo2c/6T-Pj9d3A6wJ

<comment><USER2>
      ln -s /sbin/fsck /sbin/fuck

<comment><USER3> .. and fsck you ..

</comment></comment><comment><USER4> It was probably the less benign `frck`.

<comment><USER3> fsck you ..

</comment></comment><comment><USER5>
      Dennis Ritchie:  "So umount was originally called something else"
      Question:  "what was it called?"
      DMR:  "Well, the second letter was different."

<comment><USER3> .. you're cool ..

</comment></comment><comment><USER6> Good lsck!

<comment><USER3> .. and fsck you!

</comment></comment><comment><USER7> It would be funnier if it wasn't so true.

</comment><comment><USER8> But fsck _fixes_ disks! Shouldn't it be called unfsck?</comment>


25th Anniversary of the Theatrical Release of "Hackers" - <AUTHOR> https://www.hacktheplanet.com/ <comment><USER2> Hackers did something that very few hacker movies ever did by getting the spirit of the hacker community right.

Sure, the hacking itself is nonsense, but it depicted a bunch of people from diverse backgrounds coming together in a shared love of computers and curiosity. They hack because it's interesting, challenging and fun.

As a bonus, the rollerblade-friendly arcade bar thing—Cyberdelia—is the coolest place I've ever seen.

<comment><USER3> The hacking itself isn't really nonsense at all, IMO. It's still the only hacker movie I know of that featured dumpster diving and social engineering as primary methods of learning about and gaining entry to a system.

The actual computer bits were outlandish, sure, but that tongue is so firmly planted in a cheek that you can see it from orbit.

<comment><USER4> i've always seen the flashy computer bits as something that isn't intended to be viewed literally, but rather a way to understand the mental models they had for things. in the same sense that i would explain something as "hopping into a box and poking around systemd to see what's on fire", the movie used big flashy graphics as a metaphor for the minds of expert users. i think that was the best possible choice to bring you into their world without requiring the viewer to have an expert understanding of the inner workings of a computer.

<comment><USER5> That's a great way to put it.

<comment><USER4> i think it was a really good choice, i'm certain i'm not the only person who saw that movie as a small child and decided thats what they want to be. it was exciting and cool back then and it still holds up now. i want to imagine that someone truly and deeply understood having a love and understanding of computer systems when they made the choice to express it with such artistic license.

</comment></comment></comment></comment></comment><comment><USER6> I uploaded the opening NYC flyover to YouTube in its original aspect ratio (where the city grid morphs into a circuit board): [https://www.youtube.com/watch?v=Dn8VtOAHIpk](https://www.youtube.com/watch?v=Dn8VtOAHIpk)

The main character's mother wishes him a happy birthday at the end of the opening. He was 18 then, which would make him 43 today.

About a year ago, someone posed the question on Twitter: what would Dade Murphy be up to today? My guess was making a living off of million dollar bug bounties in Apple / Google / Amazon security exploits. He was probably deep into the iOS jailbreaking scene 10 years ago, and regularly gives talks at Defcon

<comment><USER3> Or maybe he'd be making painful-to-watch corporate training videos for belaboring the point that phishing exists, like Kevin Mitnick.

</comment></comment><comment><USER7> This movie's DVD I bought in '99 while visiting the US was my first encounter with geo-blocking. If the movie itself wasn't enough of a motivator to dip my toes on the "dark side", that surely was.

</comment><comment><USER8> We went to a local theater showing of this about a year ago. It _really_ benefitted from the big screen, actually. They encouraged everyone to wear their best "hacker" costume (tin foil, punk hairstyles, even a few rollerblades) and sent us home with a floppy labeled "HACK THE PLANET".

</comment><comment><USER9> Hackers is probably a big reason I got into computers as a kid in the 90's. I wish I still had that same feeling of awe and excitement about them today.

<comment><USER10> Computers haven't changed, but the world has. It feels like hackerspaces and certain scenes still have the same energy of the web's early days.

What's changed is that the ratio of those people to the total population of computer users has drastically decreased. And furthermore, the ratio of creators to consumers has also plummeted.

Ironically, I think that's the lesson that should be taken from TikTok's success: there's actually a surprising amount of people who yearn to be more creative than currently popular platforms allow them to be.

<comment><USER11> >t feels like hackerspaces and certain scenes still have the same energy of the web's early days.

I'm not so sure. Maybe 10 years ago. I used to be involved with the hackerspace scene in the UK but I got sick of the politics. Like all subcultures, past a certain point it starts attracting the sociopaths.

<comment><USER10> That's always been true of scenes though. Especially computing where people tend to be more... "unique."

Internal politics seems like the #1 problem for volunteer groups. But then, I guess it is for the wider world as well! Anything worth anything is worth fighting to control (for some).

</comment></comment></comment></comment><comment><USER12> I watched this movie several times as a kid - in 1998 for the first time.

Many scenes were always kind of silly, but they still managed to embed this idea in my head that doing stuff with computers could be considered "cool".

</comment><comment><USER13> My favorite "hacker" movie is "Sneakers".

<comment><USER14> Well the correct answer is WarGames I'm afraid.

<comment><USER15> The Tron movies are up there for me as well. The most recent Tron movie is one of those movies that I can watch with no sound or listen with no video and still enjoy it.

</comment></comment></comment><comment><USER16> Huge nostalgia wave. 25 years later, I've recently bought an analog synth and am revisiting the big beat, ambient and electronica bands on that soundtrack, who were the backing tracks to that entire period. It was at the decade mark about 10y after cyberpunk and 10y before social networks.

Funny how back then hacking was about how to get into systems, and today it's more about how to get out of the omniscient panopticon we all contributed to building in one way or another. Maybe it hasn't changed that much at all, just less rollerblades?

</comment><comment><USER17> RISC architecture is gonna change everything!

<comment><USER18> in the mid-00's I felt like this aged very poorly.. but now?

<comment><USER6> RISC-V is a likely architecture to gain in popularity post ARM (which is also RISC). It's open source and freely licensed.

<comment><USER19> Yep, and the Year of the Linux Desktop is just around the corner too...

<comment><USER20> I've been on the linux desktop for 15+ years and what does this mean then?

You're free to live in the year of the linux desktop, each and every year. Choose your reality.

<comment><USER19> > I've been on the linux desktop for 15+ years and what does this mean then?

I've been seeing this kind of feigned obtuseness for 20 years now. It isn't cute or funny, and linux desktop is still a minority operating system even amongst the nerds it is supposedly for.

<comment><USER20> It isn't cute or funny, nor do I care what you think it is. Why would anyone care how many other people are using an operating system? Why does it matter that a certain operating system isn't used by normal people who can't use a computer in the first place?

Regardless of what you took it as, I don't own any Windows/Mac operating system computers personally and the statement wasn't funny. I've only used linux/Plan9/BSDs for well over a decade and they work pretty well. I completely do not understand why computer use has to be a popularity contest. Consider instead that once an OS has too many simple users who want GUI cruft and bloat, it then ruins the OS with slow bloated "simplifications."

There were many years in which I tried to get all my friends and family to use linux and the reality is, eventually I just realized most people don't actually wish to really use a computer. Those people who just browse social media and email and can't fix anything borked, they are not computer users anyway. The skewed stats really show that there are so many millions of Windows computers out there but really hardly anyone uses those computers to do any computing/programming/scripting/

Anyway, I didn't find your little passive-aggressive quip to be funny whatsoever, either.

</comment></comment></comment></comment></comment></comment></comment><comment><USER21> I remember watching it with friends and commenting "I have read this, this and this" when, in a well researched scene, the group of hackers casually shows off some famous CS books.

</comment><comment><USER22> The movie also helped to popularize the essay "The Conscience of a Hacker", more commonly known as the "Hacker's Manifesto" [0]. Portions of it were read in the film.

[0] [http://phrack.org/issues/7/3.html](http://phrack.org/issues/7/3.html)

</comment><comment><USER23> Soundtrack for background nostalgia: [https://open.spotify.com/playlist/4VD06iQuXulKarrsIHia40?si=...](https://open.spotify.com/playlist/4VD06iQuXulKarrsIHia40?si=2bBMMwzvQa- Lau-l6M3Kcg)

</comment><comment><USER24> The soundtrack still holds up.

<comment><USER25> That'd be Orbital's Halcyon & On & On which contains a sample from Opus III's It's A Fine Day, sung by Kirsty Hawkshaw.

There's also tracks by Leftfield, The Prodify, Carl Cox, Underworld, ... [1] [2]

Pretty much the alternative (electronic) music at that time. And what a time 90s electronic music was.

[1] [https://www.imdb.com/title/tt0113243/soundtrack](https://www.imdb.com/title/tt0113243/soundtrack)

[2] [https://www.discogs.com/Various-Hackers- Soundtrack/release/4...](https://www.discogs.com/Various-Hackers- Soundtrack/release/498401)

</comment></comment><comment><USER26> I watched that movie as a teenager like 50 times!

<comment><USER27> Same. I can pretty much recite the script from memory.

<comment><USER28> Never fear, I is here! :)

<comment><USER29> _I disguised myself as an Alabama State Trooper and penetrated the FBI NCIC._

<comment><USER10> _Pool on the roof must have a leak._

</comment></comment></comment></comment></comment><comment><USER30> It has a 28.8 bps modem!

<comment><USER31> this reminds me of a quote from this awful movie Fled ([https://www.imdb.com/title/tt0116320/](https://www.imdb.com/title/tt0116320/)):

"So fast, it's like the Ducati of computers."

</comment></comment><comment><USER32> Still inspiring hackers today! Behold the movie in C: [http://bloerp.de/code/tempel/hackers/hackersFinal.c.html](http://bloerp.de/code/tempel/hackers/hackersFinal.c.html)

</comment><comment><USER13> Hack the Gibson.

</comment><comment><USER33> I always loved Penn Jillette's (one half of Penn and Teller) character . The 90s sysadmin vibe is on point especially with the random earing in only one ear.

</comment><comment><USER25> Starring Jonny "Crash Override" Lee Miller and Angelina "Acid Burn" Jolie, both very early in their career.

Also, I believe some of the scenes contain SGI's fsv [1].

[1] [https://en.wikipedia.org/wiki/File_System_Visualizer](https://en.wikipedia.org/wiki/File_System_Visualizer)

</comment><comment><USER34> I watched this as a kid and I remember being very inspired by it and a few other movies. This together with Diablo 2 cheating/modding was the thing that made me interested in computers to begin with.

</comment><comment><USER35> Hackers features some early rendered footage from Wipeout by Psygnosis. [https://youtu.be/ATlszssL-eI?t=52](https://youtu.be/ATlszssL-eI?t=52)

</comment><comment><USER28> Still the epitome of cool.

<comment><USER36> Zero Cool

</comment></comment><comment><USER37> I find it ironic that this does not render in Firefox Focus.

</comment><comment><USER38> I was _Zero Cool_.

<comment><USER39> Man, I thought you were black!

</comment></comment><comment><USER40> Time for a reboot then!

<comment><USER28> oh hell no! time to rewatch the blu-ray. :) A reboot would get it wrong.

<comment><AUTHOR> I completely agree. This is a mosquito trapped in amber, a jewel from a different time. It must be appreciated in its context.

</comment></comment></comment><comment><USER41> I was online and I was programming back then. Why am I not a billionaire?

<comment><USER42> Because you didn't express your frustration about women by building a photo rating website and going from there at the time. I think you did well.

<comment><AUTHOR> Touché

</comment></comment></comment><comment><USER43> Hollywood computer movies are the worst, between the tropes and the stereotypes they are just Weird Science without the road warriors and Bill Paxton. The original Wargames is probably the least campy and most watchable of the bunch. From there you take he express elevator straight down to absurd and fantastical stuff like Tron and Colossus: The Forbin Project. Anyone remember Disney's The Computer Wore Tennis Shoes? Yes, computers are magic and touching one gives you all their super powers - like doing hard math and making perfect hoop shots.

<comment><USER18> I think you're right about tropes and campiness. But there's one thing that the movie did other than being realistic and that's capturing the "feeling" of a thing.

I think hackers did a good job of capturing the "feel" of mid-90s computer users. It was a new frontier, mostly celebrated by outcasts and was inherently anti-authority.

I still get the same vibe from the CCC as I got from the first time I watched the movie Hackers.

Also, people tend to forget about Acid Burn, best hacker in the movie who is only "beaten" because the other members took pity on the main protagonist. That flies a bit in the face of others in the same genre.</comment></comment>


On Being a Senior Engineer - <AUTHOR> http://www.kitchensoap.com/2012/10/25/on-being-a-senior-engineer/#

<comment><USER2> It seems to be focused on extracting value from employees, so here is a few of mine to ensure the balance:

Mature engineers don't agree to work for a lower salary just because the problem is "interesting".

Mature engineers don't work uncompensated overtime.

Mature engineers ensure that both their personal contribution and that of their peers' is given credit for and rewarded accordingly.</comment>


Pony language 0.11.0 released - <AUTHOR> https://pony.groups.io/g/user/message/892 <comment><USER2> Pony is an open-source, object-oriented, actor-model, capabilities-secure, high performance programming language.

[http://www.ponylang.org/](http://www.ponylang.org/)

<comment><USER3> I always wondered whether the language had or had not been named because of that show about colorful, pastel-, candy-colored equines, of which I'm totally not a fan of.

<comment><USER4> Have you seen the FIM++ language? Perhaps somebody should re-write the interpreter in Pony.

[https://github.com/JaredMFProgramming/fimpp](https://github.com/JaredMFProgramming/fimpp)

<comment><USER5> Oh man, but that's nothing compared to this: [https://github.com/ErisBlastar/cplusequality](https://github.com/ErisBlastar/cplusequality)

</comment></comment></comment></comment><comment><USER6> Actors + type safety is a huge selling point for Pony that, to my knowledge, no other language is really providing.

I'm definitely keeping an eye on it and I'm very excited to see its development continue.

<comment><USER7> The distributed-process (Cloud Haskell) library gives you Erlang-style processes/actors in Haskell. Haskell is a good language to map these concepts to since it already has lightweight threads, pattern matching, asynchronous exceptions and other language features required to faithfully implement Erlang semantics.

Scala/Akka would be another choice but it has totally different semantics from Erlang, and you can never forget you are working in an async model.

<comment><USER8> I think there is some misunderstanding of what Pony is. It doesn't target distributed systems by the looks of it, it's more like a statically typed OO language with an alternative to threads/mutexes/channels. So you can see it being interesting to people with statically typed OO background, who understand the downsides of multithreading and want concurrency and parallelism on a single system, i.e. those coming from languages like Java and C++. It's more appropriate to compare it with Rust or Go, but not Erlang or Akka.

<comment><AUTHOR> I'm not sure why you would say that Pony doesn't target distributed systems. In the sense that there is no "distributed pony" yet, then yes.

I spend my days writing a soon to be open sourced distributed system in Pony. The "alternative" to threads/mutexes/channels is actors which from a concurrency model perspective makes it very like Erlang. The GC model is also very like Erlang.

In the end, it is its own thing.

<comment><USER9> What's a good use for distributed Erlang? I'm writing some Elixir apps, and I can't think of a great reason to use distributed between a client and a daemon running on the same box.

<comment><USER10> Why are you specifying that they're on the same box? You can use distributed erlang between different computers and the messaging remains the same even in those circumstances.

On top of that you also get automatic failover for distributed apps(0) that are supposed to run on only one node at a time, handled entirely by the runtime, with takeover, etc.

If you're using Elixir, you should probably actually read up on the technology you're using. These are basic concepts explained in, for example, "Programming Erlang".

0 - [http://erlang.org/doc/design_principles/distributed_applicat...](http://erlang.org/doc/design_principles/distributed_applications.html)

<comment><USER9> I've got an Elixir app running as a daemon to manage cleaning up some certain build related files for a build system. The daemon is a release started by the init system. N clients might call the daemon, and the daemon makes sure the files needed for the build, or maybe left over from the last build, or in the correct state. The client could talk to the daemon via a socket or TCP port, but distributed Erlang would also be an option.

<comment><USER10> I would say when it comes to client-server interaction in Erlang, it's fine to make that as if it were any other language, but there are plenty of situations where you'd like to spin up several nodes of something in AWS, for example, and those would necessarily have to talk to each other.

You'll set up the ability for them to coordinate (by simply setting their longnames and setting them all up to connect to one machine, making them create a mesh network) and transparently you'll now have several machines working on something as if they were one, with minimal effort on your part.

The big downside to using distributed erlang is that it has very little to offer in terms of security. If you don't add something yourself (which admittedly isn't too hard) you'll be relying only on a common password for connecting to the mesh, as well as knowing which machine to connect to. Obviously it makes for a situation where it's best and most appropriate to use on your private network, setting up other means of communicating with public networks.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER11> I have to admit, the name of it throws me off. The intended or unintended relation with the subculture of obsessed adult men with a pre-teen show, and this programming language's name really makes me not want to take it seriously.

I love to judge things for what they are, and not what they're named or related too, but given there's so many languages fighting for my attention, this one is hard to swallow.

</comment><comment><AUTHOR> The 2017 Pony Community Survey just went up. If you are a Pony user or have played around with, we'd love to hear from you.

[https://goo.gl/forms/5qAmppwIEkvvEFkq1](https://goo.gl/forms/5qAmppwIEkvvEFkq1)

</comment><comment><USER12> Here is a really great, very high performance, full featured c++ library for actors:

[https://actor-framework.org/](https://actor-framework.org/)

</comment><comment><USER13> I wonder, where does ponylang fall short? I think that might be an interesting way to compare it to other languages.

<comment><AUTHOR> I'm on the core team and I'm working on a "Why Pony?" talk that starts with all the reasons you wouldn't want to use Pony. There are many.

I'd be happy to discuss via email if you want. My address is in my profile.

</comment></comment><comment><USER14> Curious what the deployment story for this looks like compared to things like Crystal. Is it compiled?

<comment><AUTHOR> Yes. Pony compiles to LLVM bytecode and from there to native binaries.

<comment><USER2> So it has Rust and C++'s compile time problems?

<comment><USER15> What would you suggest someone use instead? As someone looking to write his own language, I'm very interested in alternatives to LLVM.

<comment><USER16> Using a system like LLVM locks you into C-like behavior. You can work around it, but it's harder and can come with unnecessary overheads.

Nanopass is one approach to compiling that tends to be more general.

However, LLVM is great if you just want to compile without learning the intracies of assembly. It even gives you access to multiple backends.

Linking against a framework let's you get up to speed faster, and someone else handles the security in your compiler, for the most part.

But, when you need flexibility, you'll probably need to do it yourself.

(See Scala and Dotty, as Scala becomes even less Java-like).

</comment></comment></comment></comment></comment><comment><USER17> Pony is amazing, I am curious about the object capability model applied to distributed systems.

<comment><USER18> [http://erights.org/talks/thesis/markm- thesis.pdf](http://erights.org/talks/thesis/markm-thesis.pdf) has several chapters dedicated to the concept. Happy reading.

<comment><AUTHOR> that's an awesome paper. thank you for posting it.

</comment></comment></comment><comment><USER19> Can anyone comment on the level of development?

I came across one comment where the author seemed to think the main gurus were no longer working on it. e.g. here: [https://www.quora.com/What-is-your- experience-with-using-Pon...](https://www.quora.com/What-is-your-experience- with-using-Pony-programming-language)

I myself don't have much knowledge of Pony,which is why I ask...

<comment><AUTHOR> Sylvan (referenced as main guru in the link) is still an active member of the Pony community and he's contributing on a regular basis. His most recent commit that was merged to master was yesterday:

[https://github.com/ponylang/ponyc/commit/eaf1dcd525c691feae1...](https://github.com/ponylang/ponyc/commit/eaf1dcd525c691feae1b3e569d1fe52b2fa08749)

The Pony development community is still relatively small but we make good regular progress. We all wish the community was bigger and we were progressing more quickly but that is always going to be the case.

We have a regular weekly development Zoom call that is open to the public. Feel free to join. Info is available in the Pony development groups.io group: [https://pony.groups.io/g/dev/calendar](https://pony.groups.io/g/dev/calendar).

If you join the development list, you'll also get access to the recordings of the sync meeting going back close to a year. There's a wealth of info there for anyone cares to dig in. Probably more than anyone would care to ever listen to.

<comment><USER20> Sylvan is busily working with his team on the feature for distributed actors at Microsoft Research.

* Type-system for machine specific data (local vs foreign actors, e.g file descriptors, ...)

* Node failure

* Distributed GC (pointer identity => random id)

* Distributed work-stealing (CNF-ACK protocol, user-specific scheduler rules: moving cost, ...)

There's also more work going for more formal proofs.

Here is a bit of explanation: [https://www.youtube.com/watch?v=KIziz1c41ww](https://www.youtube.com/watch?v=KIziz1c41ww)

"Development status: Everything we talked so far is real and is in use. Runs on everything from a Raspberry PI to 4096 core SGI Windows OSX Linux FreeBSD Performance is competitive with C/C++, often better as core counts go up"

Esp. the last 10 slides.</comment></comment></comment>


The Lowdown on Lidar - <AUTHOR> https://docs.google.com/file/d/0B941PmRjYRpnX3ZqLWlQMGdGXzQ/edit <comment><USER2> I confess I was expecting to not care for this. I'm not sure how any of it should be surprising, as it seemed fairly straight forward analysis of the tools.

That said, this was a ridiculously fun read. More detailed than expected for some parts, and always informative. I'm glad it did not come across as anti speed detectors. Really more of a "know the limitations."

<comment><USER3> I hope he realizes this, as much as I hope everybody else realizes this, that the only reason why he got the violation reduced was because he brought his attorney on board. Anybody who lives in California whose contested a ticket knows that 9/10 times (if not even more than that) judges side with the officers -- whether they have a strong case or not -- the State of California certainly doesn't want it's residents to get any ideas.. if you know what I mean.

I wonder if his attorney cost more than the actual citation? Most people can't afford lawyer fees, so cops in California get away with this small stuff all the time without any fuss, whether they were liable or not. Congrats Joshua Block -- BTW I loved "Effective Java"!

<comment><USER4> I'm surprised they exonerated him, considering his driving history...

Turns out he apparently blew a red light with his Boxster in 2010 and hit another car:

[http://attitudeofgratitude.typepad.com/attitude_of_gratitude...](http://attitudeofgratitude.typepad.com/attitude_of_gratitude/2011/11/one- year-later.html)

<comment><USER5> That's a strange story. According to the blogger's version og the incident, he was struck an injured by someone clearly breaking the law. Why wasn't the other driver detained by police and arrested?

</comment></comment></comment></comment><comment><USER6> Speed radars are good for speed traps, but not so great to prevent speed related incidents. They share the same fatal flaw with all other single-point speed meters: You can just slow down for a minute, while you pass by the speed trap, and then speed up for the rest of your trip. Instead, a 2-point speed meter (i.e. license plate readers every few miles, measuring time between matching reads) system is superior because a) their margin of error is negligible and b) they measure sustained speed over a long distance rather than at a single hot spot, thus making roads safer. I can't believe it's not implanted at least in all interstate freeways.

<comment><USER7> Possibly because the cost/benefit just isn't there.

In the UK, the data shows that speeding (excessive speed for the conditions above the speed limit) is the primary cause in single digit percentage of accidents. I believe there's data from 1996 and 2007 for this, will dig it out when I'm not on mobile.

If you want to spend money on accident prevention, there's much better things to target than speeding.

<comment><USER8> I have yet to get into an accident, but I actively avoid walking across several streets in Seattle because of a combination of entitlement thinking (This road is mine because I'm in a car!), and pervasive speeding. I'm not the only one...I recently found out almost nobody on my side of a local road will cross the road due the same problem. The road, therefore, has become a barrier to commerce and has split a community in two.

Preventing accidents isn't the only reason to enforce traffic laws.

<comment><USER9> There aren't any traffic lights and crosswalks on this street?

<comment><USER8> There are some crosswalks, 8 blocks away from each other. No lights for at least a mile. In WA state, every intersection is automatically a legal crosswalk with pedestrian right of way (unless marked with a "No Pedestrian Crossing" sign), but the lack of enforcement combined with the high speeds makes that right of way effectively meaningless.

<comment><USER10> I walk a _lot_ in CA. Not long ago I saw a cop not yield to a pregnant woman pushing a baby in a stroller, in a 4 lane road. She was in the crosswalk, clearly marked. There was no light or stop sign, but she was in the middle of the 4 lanes when the cop drove past her in the closest lane. I really couldn't believe what I was seeing.

When the cops don't even respect the laws, the laws are meaningless.

<comment><USER11> This doesn't surprise me. I walk a lot too, and I constantly see cops flip their lights on for the few seconds required to make an illegal left turn, run a red light, etc., and then turn them right back off.

<comment><USER12> Yet another consequence of police immunity from prosecution.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER13> LIDAR sucks and there is no judicial notice on it in California. If you ever get a LIDAR ticket, do a trial by written declaration (or TBD). Just state that you dispute the validity and accuracy of the LIDAR reading and they'll usually throw it out. Remember to ask the officer(after he has given you your ticket) what model laser/radar detector he was using, and at what distance he measured you at. Anything over 800/1000 ft(this is really close, and rarely do they get you this close) will usually automatically be struck down if you question LIDAR's validity at that distance. That is a case you will win every time, if you do it right. The court cannot prove it's accuracy at these ranges and they know it. Also, rule of thumb, all CHP officers have laser only on their bikes now. source: I used to have a Lancer Evolution

<comment><USER14> >> Remember to ask the officer(after he has given you your ticket) what model laser/radar detector he was using, and at what distance he measured you at.

That's an interesting point. Would that be admissible, though? Wouldn't you saying "He said it was at X feet" would be considered hearsay in court, versus a cop saying "I took a reading at X/2 feet"?

<comment><USER13> He/she should normally write it on the ticket(pretty sure they have to, it's always been there on tickets I've seen), but if you can get him/her to say it out loud, it's evidence that you can probably use against him/her. Also you should record your interactions with all officers. My final not a lawyer advice on beating speeding tickets: shut your mouth and don't answer the officers questions. If the officer asks how fast you were going, nothing you can say helps you, especially "I don't know". Just do your best to be polite, but firm, and don't give him anything more than a nice attitude

<comment><USER15> This isn't always the best strategy. If you're unlikely to make a court date, being remorseful and apologetic has a decent chance of getting you a reduction from the officer. If you play hardball, so will he, then you have no choice on going to court if you want a reduction.

If you're in serious trouble, STFU is the correct choice, but it's not necessarily the most economical for a moving violation.

<comment><USER16> In Virginia, all moving violations are arrestable offenses, so I grew up doing STFU. My understanding is that most states are not that way though.

</comment></comment></comment></comment></comment><comment><USER17> As a college intern at a national lab my boss' boss got a speeding ticket on the military base we worked on. He spent some time doing research and when he presented his evidence in court the judge apparently told him he wasn't going to have to pay the fine but the judge wasn't going to find him not guilty because he wasn't going to risk invalidating all speed gun findings. I don't recall if it was lidar but it's funny the stories are so similar. It's hard to use technology to mess with engineers. :)

<comment><USER18> Lower courts (even in the Military) can't really establish any meaningful precedence

</comment></comment><comment><USER19> I think he missed a couple important points. The sweep effect, shaking and aiming are more amenable to signal processing than it seems, depending on the resolution and noise in the system. I tried to illustrate in pictures:

1) Just to demonstrate that a nonuniform sweep is amenable to detection or processing, consider this picture, with the correct estimate in green: [http://imgur.com/FsPAwCn](http://imgur.com/FsPAwCn)

2) Now imagine the device is more sophisticated. Consider it has a very large resolution around the incoming pulse: [http://imgur.com/z8UrhUw](http://imgur.com/z8UrhUw) In this case the beam width is actually beneficial, and so are large distances. The sweep effect would cause a shift in the peak intensity shown in the graph, but the object depth frustrum should be clear across samples (and dislocating at t'=t-v*dt/c).

3) Officers can be trained to recognize situations unforable, regardless of distance. One fast car passing a slow one would make it easy to confuse the equipment. A clear desert however doesn't present many threats for error.

<comment><USER20> I think its funny how he claims location sampling at different times is not a measurement of speed.

It's strange how he mentions the sampling speed, but then pretends it's 1/3 second. Basically what he is attacking is the worst design of a speed gun that he could imagine from the public information. A more fair challenge would be to find sufficient error from a competent design of a speed gun, but then it wouldn't be as self serving.

</comment></comment><comment><USER21> When I was a teenager I tried to fight a speeding ticket, and prepared a presentation like this with several good points (I think).

Come court day, I got all dressed up, stood up when called and started my arguments ... and the judge simply cut me off after two sentences and said "guilty".

I'm surprised this guy was allowed to present his whole argument and it actually convinced a judge.

<comment><USER22> Did you appeal? You can always appeal your first court hearing. The key is to talk to the prosecutor beforehand. They will almost always plea it down.

<comment><USER21> This was in Maryland. It seemed you went right to the courtroom and talked to a judge along with 40 other people. There was no prosecutor present as far as I could tell.

I've fought them in Connecticut later and there you only meet with a prosecutor and they warn you all over the place that if you don't take the deal and try to go to court the judge can significantly increase the fine :-(

</comment></comment></comment><comment><USER23> Can anyone tell me why speeding tickets aren't enforced with video cameras (like red-light tickets are)? It would seem to be much more accurate, much easier to enforce, and much harder to dispute.

Irrespective of the rights or wrongs of speed limit laws, I do believe that consistent and efficient enforcement can only be a good thing.

<comment><USER24> In Ireland we have a system where you can contest any of these automated fines in court. The problem is that the fines and penalty points double should you contest and lose. [http://en.wikipedia.org/wiki/Penalty_points_in_Ireland](http://en.wikipedia.org/wiki/Penalty_points_in_Ireland)

<comment><USER25> How is that even legal? It seems like it would infringe on the requirement of due process anywhere in the world.

<comment><USER26> That's just a more formalized version of a plea bargain. (Whether plea bargains are just as much a due process violation is not part of my post.)

</comment></comment></comment></comment><comment><USER27> I hope this information, or the equivalent, filters into the awareness of judges. I was in traffic court in Virginia last year and, as I was waiting for my case, heard the judge explain to several defendants who were there to challenge their lidar tickets that the lidar was essentially infallible and could not be confused by other cars on the road. And this was an intelligent judge who seemed unusually sympathetic to the accused.

<comment><USER28> Unfortunately judges are people and if you have tons of people coming in with just "LIDAR is not accurate enough to prove reasonable doubt" compared to cops bringing in studies proving their accuracy it is difficult to listen to it.

</comment></comment><comment><USER29> Anecdotally, I heard of an astronomer in a similar situation, who attempted to prove the radar gun used to "catch" him speeding was incapable of measuring the speed accurately enough (presenting info on the radar gun's sampling properties and on sampling theory; I forget the specifics). Supposedly the judge maintained the speeding violation but reduced the man's fine for "entertaining the court".

</comment><comment><USER30> Josh Bloch is awesome.

For the non-java inclined, he wrote (among other things) java.util.HashMap. Most all Java programs run (lots) of his code.

<comment><USER31> I know him as the author of the awesome "Effective Java"

<comment><USER32> I know him as the guy who advocated the even wider use of factories...

</comment></comment></comment><comment><USER33> In Michigan, a speeding ticket is a civil infraction, not a criminal offense, so the legal standard is _preponderance of the evidence_ , not _beyond a reasonable doubt_ , as the slide deck says. I suspect it's the same in California.

<comment><USER34> In CA, infractions are crimes so the reasonable doubt standard applies. See Cal. Pen. Code section 16. [http://law.onecle.com/california/penal/16.html](http://law.onecle.com/california/penal/16.html)

<comment><USER35> Wait a minute, if that's true won't it imply that traffic violations/infractions convictions get you a criminal record ?

<comment><USER34> Yes. Infractions are crimes so yes. For the most part, they are not treated as crimes. You cannot be jailed based on an infraction. Most job applications I've seen typically explicitly exclude requiring information about past infraction violations.

</comment></comment></comment></comment><comment><USER36> I have lidar jammers on my car, but Arizona doesn't use a lot of lidar. (Motors and sometimes bored DPS will, but typically it's Ka band radar via Stalker Duals.) Not really knowing how lidar worked, except that a "laser" pulse hits the car and reads back a speed, this article was great because it explains that the measurement process is far slower than you'd think (0.3 seconds!) which is easily enough time for my jammer to detect the inbound infrared and start spamming light on that frequency, which is what they do.

I don't think I've ever successfully jammed one, since again, AZ is mostly Ka, but it's pretty neat to know that they can work as advertised (since they're built in to the front of the car most likely to be targeted by lidar).

<comment><USER37> I've read that in some jurisdictions police have started confiscating jammers and even charging users with obstruction of justice, on the theory that while owning them is explicitly legal, using them prevents police from carrying out their duties. Do you know what the history in AZ is like?

</comment></comment><comment><USER38> All the talk in this thread about various forms of speed management and fines remind me of an article I read a while back about a Swedish test program that used fines from speeders as the funds for a lottery that people driving at or under the limit were entered into automatically: [http://www.wired.com/2010/12/swedish-speed-camera-pays- drive...](http://www.wired.com/2010/12/swedish-speed-camera-pays-drivers-to- slow-down/)

</comment><comment><USER39> The highlights:

1\. Lidar gun manufacturers test them on limited and ideal circumstances

2\. Beam divergence and shakiness make them less useful past 1000 feet, which is generally acknowledged.

</comment><comment><USER40> Excellent presentation with considerable technical information, e.g., weaknesses in the LIDAR approach, operational realities that reduce accuracy, etc., and some legal background, e.g., limiting LIDAR to 1000' or less in some jurisdictions - but contrast with overall lack of case law.

Could be of value to anyone wishing to fight a ticket.

</comment><comment><USER41> Perhaps anyone can explain me why Lidar is not dangerous to sight?

Whenever you see anyone working with lasers they'd wear protective glasses. Now I realise Lidar uses infrared wavelength which is not visible to us, but that does not mean it's not dangerous, or does it?

<comment><USER42> Non-visible lasers pose a much bigger hazard than visible. Intense visible light triggers an involuntary defence called the blink reflex whereby we blink before the retina absorbs enough energy to get damaged. Lasers outside the visible range don't trigger the blink reflex and can destroy the retina before you know what happened.

Lidar operates at relatively low power and relies on very sensitive detection in a very narrow wavelength range to identify reflections.

</comment></comment><comment><USER43> The reading was taken at a distance of 1300 feet with a handheld device that is not meant to be used handheld beyond 1000 feet. That's a significant distance. I'm assuming the cop was hiding or trying to stay hidden.

</comment><comment><USER44> A lot of this is common knowledge now. You can check out guys of LIDAR who research these types of guns & how accurate their findings are. This is also why cops should be taught to do several speed readings & to point at the vehicle, not the headlights. Also, depending on the paint, it can also cloak the vehicle's speed or make it take longer to get back to the gun.

</comment><comment><USER45> Next time I get a parking ticket, I'll be sure to investigate the temperature stability of the parking meter's clock.

</comment><comment><USER46> I'm surprised the angle of measurement never came up. Isn't it the case that a reading has to be head-on for it to be accurate? It seems pretty obvious that at higher angles the observed distance delta will be smaller.

</comment><comment><USER47> I've wondered sometimes if it would be possible to fight erroneous speeding tickets using the repeated GPS pings your phone or nav unit makes while using them for directions.

</comment><comment><USER48> Well, he fought with half science: he came up with a set of testable hypotheses, but didn't actually run any of the tests. I guess that's as scientific as cosmology :-)

<comment><USER49> It's not even half science, it's just a big slide deck of FUD padded with a healthy amount of entitlement.

<comment><USER50> Be honest with yourself: If you got a ticket where the indicated speed was massively different than the speed you were actually travelling, you'd fight it too. And you might do some research into the validity of the reading, as well.

You'd especially do it in a state where the law says "x" mph over the limit and your license may get suspended (meaning you walk for 60 days). It'd be worth fighting for.

<comment><USER14> Especially if it were in a residential area where you had been deliberately careful. If I got a ticket saying that I'd been driving 40 in a 25 zone, when I had been carefully watching my spedometer at ~20s, I'd feel pretty wronged.

I'm not sure I'd have the resources to fight it, but I would certainly want to.

</comment></comment></comment></comment><comment><USER51> So regardless of the science behind it, what is the successful legal forum / mechanism to raise doubt about the accuracy of the technology being used by police?

</comment><comment><USER52> How does the officer confirm which vehicle the LIDAR selected? I have never been clear on this point.

<comment><USER53> I believe they have "sights" and are aimed like a gun.

<comment><USER54> Cops routinely shoot innocent bystanders.

</comment></comment></comment><comment><USER55> now if only somebody published a similarly powerful defense on "traffic control device violation" :)

</comment><comment><USER56> Well the author may be a clever computer scientist but he knows nothing about physics and LIDAR equipment. Pathetic I'm afraid.

<comment><USER57> Given that (1) you're an expert in these areas and (2) you found no points in the author's work worth refuting, I guess it follows that the author is actually an expert as well.

</comment></comment><comment><USER25> Why do HN mods keep changing the title from meaningful ones, which make the reader interested in the content, to generic, vague ones? You'll see that there's definitely a correlation between the moment that HN mods change the title and the post dropping off the top frontpage spot.

<comment><USER58> I'd really like to see more transparency when it comes to title changes. The most recent case where one of my submissions had a title change mirrors what kudu is describing here: a meaningful (and I think accurate) title changed to a generic and vague one -- followed by a rapid decline in the rate of upvotes. I think there are legitimate reasons for title changes, and I think that the Hacker News mods generally do good work. But sometimes they seem to be fixing stuff that isn't broken. I realize titles in particular can be really subjective, but that's one reason I'd like to see a comment with the old and new titles whenever a title change happens. That will allow the community to chime in when maybe the title change wasn't an improvement after all.

<comment><USER59> _" I'd really like to see more transparency when it comes to title changes."_

I think _dang_ is working hard to be transparent about this topic. You can see a number of examples of this by reading through the following search result [1].

Cases in point:

He has reverted titles to their original form... "Ok, we'll change the title back again." [2]

He is open to suggestions...

"If anyone suggests a better title, I'll change it again." [3]

"That's a fair suggestion and we changed the title accordingly." [4]

"We'd happily change the title if someone can propose a more accurate and neutral one." [5]

[1] [https://hn.algolia.com/#!/comment/forever/0/author%3Adang%20...](https://hn.algolia.com/#!/comment/forever/0/author%3Adang%20title%20change)

[2] [https://news.ycombinator.com/item?id=8050702](https://news.ycombinator.com/item?id=8050702)

[3] [https://news.ycombinator.com/item?id=7557464](https://news.ycombinator.com/item?id=7557464)

[4] [https://news.ycombinator.com/item?id=8104621](https://news.ycombinator.com/item?id=8104621)

[5] [https://news.ycombinator.com/item?id=7959549](https://news.ycombinator.com/item?id=7959549)

<comment><USER60> Title changes are a perennial point of friction. Much time and energy by many parties has been spent over months debating and analyzing it.

Why not just implement a title history feature? Mods can change title, then users can click a link to show title history.

For extra points, you could make the title history page a poll/voting system which allows users above n karma, registered for x months to vote on their preferred title. Top voted title after y votes and z time after initial title change is what's used.

<comment><USER61> I definitely like the option of a title history + voting on which you believe is a "better" title. I also agree that limiting it to a certain threshold of karma, account age, etc, is appropriate.

</comment></comment></comment></comment></comment><comment><USER62> Don't Google's self driving cars use LIDAR.

<comment><USER63> They probably take all of these things into account.

If they didn't, I suspect Google's self driving cars wouldn't use LIDAR.

</comment></comment><comment><USER64> Exec summary: a geek/nerd gets a speeding ticket driving a porsche. 5 years later he's still doing powerpoints on it rather than getting a life

</comment><comment><USER49> Alternate title: some guy says he was doing the limit in a Porsche.

<comment><AUTHOR> My clickbait technique is impeccable.</comment></comment>


Belgian railway operator uses AI to check mouth mask use - <AUTHOR> https://translate.google.be/translate?sl=auto&tl=en&u=https%3A%2F%2Fwww.nieuwsblad.be%2Fcnt%2Fdmf20200525_04971068 <comment><AUTHOR> Infrabel, which manages the railway infrastructure, uses artificial intelligence to check whether employees wear their mouth masks properly and keep a sufficient distance.</comment>


Show HN: APId now has an interactive playground page! - <AUTHOR> https://www.getapid.com/playground <comment><AUTHOR> Hey all, the co-founder of APId here. Today we've launched a new page on our website specifically targeting new users. The page is a playground to test your suites and is powered by our cloud.

This is mainly to help new users onboard faster and let them experiment without any setup needed on their part!

Thanks!</comment>


Stilumus – New JavaScript Framework from Basecamp is out - <AUTHOR> https://github.com/stimulusjs/stimulus <comment><USER2> Name is wrong, it's called "Stimulus" (I guess from 'to stimulate'), not "Stilumus".

</comment><comment><USER3> It's available on github, but "out"? It seems they're still gearing up for a 1.0 release.</comment>


Ask HN: Why doesn't Google make an IDE? - <AUTHOR>

Google seems to be releasing a lot of products with a goal of speeding up the web. So why not make an IDE? <comment><USER2> Google supports Eclipse plugins for GWT, GAE & Android.

<comment><AUTHOR> But it's not the same as building an IDE from scratch.

<comment><USER3> How would building an IDE from scratch be better? Why not just improve Eclipse? How is Eclipse deficient, anyway?

</comment></comment></comment><comment><USER4> Because they don't need to.

Eclipse is a good platform that can supports anything they ever need through plug-ins.

</comment><comment><USER5> Because it is no longer the late 90's when everyone and their dog was building new IDEs.</comment>


Show HN: Publish a Blog from Google Sheet - <AUTHOR> https://blog.andreyazimov.com/ <comment><AUTHOR> Show HN: Publish a blog from Google Sheet

Hello HN!

I previously created Sheet2Site.com, it lets you generate a website from a Google Sheet. A lot of users asked me how they can create a simple blog in the same way.

So I made a super simple blog in a single spreadsheet. It support Markdown for posts, and has support for a image header, nav bar, logo. Everything can be changed inside the sheet.

It also has Markdown live preview, to see how what you're writing will look like. And basic features like social media cards with images and custom CSS/JS.

I decided to move my personal blog from Medium. I used it for 2 years, but not it's just annoying.

Here's a blog demo: [https://blog.andreyazimov.com/](https://blog.andreyazimov.com/)

And here's the source spreadsheet: [https://docs.google.com/spreadsheets/d/1M_T1V_WIg4AYK7QmugFo...](https://docs.google.com/spreadsheets/d/1M_T1V_WIg4AYK7QmugFoBYqGYryQJvis4dvwTZv5CsU/#gid=1775114236)

Let me know what you think, I'd love feedback.

</comment><comment><USER2> What I might like better is if you can publish a blog from a NNTP feed. If there is a article which has some sort of verification and lack a "References" header, then it appears as a blog post; if there is a "References" header then it will appear as a comment, and users can post comments using NNTP.

Markdown would work, due to two advantages they have: It is easy to read even if it has not been rendered as Markdown, and there is a MIME type defined (so that a NNTP post using Markdown can have a "Content-type" header to indicate that). This is unlike bbcode, which doesn't have these advantages.

<comment><USER3> What would be the usage? What news do you want to transform to a blog post?</comment></comment>


Coronavirus: The science seems to indicate that facemasks are a winner - <AUTHOR> https://www.fast.ai/2020/04/13/masks-summary/ <comment><USER2> What if I never cough nor speak nor touch my face (yes, I'm sufficiently mindful to be sure) as I walk outdoors - what does wearing a mask change then?</comment>


How to build an ACID compliant database with only 24 bytes of mutable data? - <AUTHOR> http://www.elekslabs.com/2012/11/a-deep-look-into-event-store.html

<comment><AUTHOR> What if I told you that the new Event Store (OSS geteventstore.com) is an ACID compliant database with only 24 bytes of mutable data? This session will look deep inside the Event Store and architectural decisions and trade offs made in the development of it.</comment>


Ten Technologies That Will Rock 2010  - <AUTHOR> http://www.techcrunch.com/2010/01/01/ten-technologies-2010/ <comment><USER2> I'm particularly interested in the public vs. private trend.

</comment><comment><USER3> Where's JooJoo?

</comment><comment><USER4> Seems like 2010 is the year of lists!</comment>


Is the Mojave Phone Booth Down? - <AUTHOR>

<comment><AUTHOR> Even the SMS seems to be not responding: 760-733-9969

[https://en.wikipedia.org/wiki/Mojave_phone_booth](https://en.wikipedia.org/wiki/Mojave_phone_booth)</comment>


The Science of Shopping (1996) - <AUTHOR> http://www.gladwell.com/1996/1996_11_04_a_shopping.htm

<comment><USER2> Would love if you can share a similar article on online shopping - that'll immensely help this forum. We all are trying to create something that we would be able to offer online, or have people pay for subscription, or what have you. Would like to get into deeper psychology discussion on what makes people make such decision. Any thoughts? Articles?

<comment><USER3> I think Jacob Nielsen is probably an expert in this field: <http://www.useit.com/> (beware of a really ugly design).

Other than this, I think the safest bet is to trust the data, e.g. A/B testing. Being too smart without any testing could lead to fatal mistakes - Google has thousands of phd's and they still trust real user testing more than "opinions" (at least according to Peter Norvig :)).

Paco Underhill seems to use the same method, i.e. observing real customers and then drawing conclusions.

<comment><USER2> Thx Amix. I was not aware of the site. Seems a very good resource, though its usability centered. I would still like to see some discussion around the original post - with web emphasis.

<comment><AUTHOR> Perhaps like: <http://www.nngroup.com/reports/ecommerce/checkout.html>

<comment><USER2> Well, again, that link is design oriented. I guess I'm looking for a similar article to what the original topic was about: "Science of _online_ shopping"

<comment><USER3> I think majority of their analysis is by looking and analyzing real e-commerce customers by video, hot maps etc. - i.e. they basically do the same thing Paco Underhill does (thought Paco is probably a lot more detailed in his approach).

</comment></comment></comment></comment></comment></comment><comment><USER4> One thing I wonder about the invariant right is if it changes in countries where people drive and walk on the left side.

</comment><comment><USER5> Wouldn't it be great if such meticulous studies were done on other things, such as education?

</comment><comment><USER6> I remember reading this when it came out.</comment>


Blackbird: Bitcoin arbitrage - <AUTHOR> https://github.com/butor/blackbird/blob/master/README.md <comment><USER2> Two notes. First, as others have said, while the market may contain inefficiencies, they tend to close fast especially with a public solution. That said, this may be a good starting point for you to go nuts on for generation 2.0 so enjoy the code.

Second, while I won't comment on this particular strategy, I want to note that many so-called "arbitrage" systems are actually sleeves for another important risk: liquidity. These strategies typically assume normal trading behavior and don't take into account that exchanges break during crisis events, the exact events (even if they're rare "black swans") which can leave you half in a trade and wearing massive exposure during extreme volatility. The analogy is picking up nickels before a bulldozer... use at your own risk.

<comment><USER3> huh, you give an analogy w/ out actually explaining how this would happen.

<comment><USER4> I think that poster does explain how it happens. The exchanges tend to shut down or break during extreme volatility events. If one breaks and the other doesn't, you're half in the market. What if you can't sell your positions until after the price drops, but the other position doesn't exist to balance it out?

<comment><USER5> With cryptocurrencies you also have other exchange risks, notably the risk an exchange is hacked or otherwise goes out of business. Imagine if you had been buying BTC on Coinbase and selling BTC on MtGox in 2013, making a great profit (on paper) through arbitrage, until MtGox tanked and all those profits were frozen.

</comment></comment></comment></comment><comment><USER6> For people wondering, does it work? Short answer. No.

Long answer - The biggest flaw lies in the "advantages" section:

 _Unlike other Bitcoin arbitrage systems, Blackbird doesn 't sell but actually short sells Bitcoin on the short exchange_

The problem is only Bitfinex allows _short selling_. So, the example is an excellent case of cherry picking.

There are other issues with their strategy too.

<comment><USER7> Also Bitfinex uses Tether tokens, not USD, which are by their own terms of service worthless, and it's dubious as to whether their actually backed by any real USD.

This arbitrage exists because of the huge counterparty risk of exchanges

<comment><USER8> I thought you were being hyperbolic about Tether tokens being worthless. Turns out you're completely right: [https://tether.to/legal/](https://tether.to/legal/)

> Tethers are not money and are not monetary instruments. They are also not > stored value or currency. There is no contractual right or other right or > legal claim against us to redeem or exchange your Tethers for money. We do > not guarantee any right of redemption or exchange of Tethers by us for > money.

> We make no representations, warranties, or guarantees to you of any kind, > including with respect to any right of redemption or exchange of Tethers for > any property.

That doesn't make any sense. Those are absolutely _outrageous_ terms of service for what Tether purports to be.

I thought the _entire point_ of Tethers is that they're redeemable for USD on a 1-to-1 basis with a fixed exchange rate. That's exactly what the Tether FAQ says, but based on the actual ToS, I'd have to consider these statements to be absolute bullshit:

> Tether Platform currencies are 100% backed by actual fiat currency assets in > our reserve account. Tethers are redeemable and exchangeable pursuant to > Tether Limited's terms of service. The conversion rate is 1 tether USD₮ > equals 1 USD.

[https://tether.to/faqs/](https://tether.to/faqs/)

The FAQ says "Tethers are redeemable[] pursuant to Tether's terms of service" and the ToS says "There is no contractual right or other right or legal claim against us to redeem or exchange your Tethers for money"

That is just fucking outrageous. I'm sorry, but it is.

I do not understand how or why anyone would use Tether without a contractual guarantee from the issuer to redeem each token for the underlying currency that it reserves. Without this, there's no reason for Tether to have a value.

I thought that the concept of Tether had sound technical merit -- essentially, a cryptocurrency with a fixed exchange rate backed by a full-reserve central bank for each currency -- but when offered with those legal terms, I have to consider it a scam. Under their ToS, money can flow into Tether but not out!

I can speculate about all sorts of reasons why they might have put up those ToS, but at the end of the day, it's a morally wrong contractual relationship for them to have with their customers. They should operate like a bank or otherwise with a guarantee that customers can convert Tether back to the reserve currency.

Edit: While doing some searches on this topic, I also found a news article about their questionable ToS, quoting this statement from the company:

> Our Terms of Service have been carefully picked apart by various malcontents > and twisted to suggest that Tethers would not be redeemable for currency on > some bizarre, malicious whim by Tether. That is untrue. > [https://cointelegraph.com/news/tether-really-isnt-a-scam- > com...](https://cointelegraph.com/news/tether-really-isnt-a-scam-company- > promises)

Yeah, okay guys ... this interpretation is not carefully picking apart the ToS with malcontent. It's just a basic plain English reading of the ToS. I would stay away from Tether, and any company that responds in this way to completely reasonable criticisms.

<comment><USER9> And you can't withdraw anymore. [0] The whole trick was that Bitfinex could claim to have a price for USD, because they have a price for USDT, and the ratio of USDT/USD is 1. But since they've printed over 1 billion USDT without any assurance that they have USD to back them up, and now you can't withdraw at the source for the USD that they supposedly have backed in a bank somewhere, expect the value of USDT/USD to plummet on exchanges. Fun times.

[0] [https://tether.to/wallet-service-and-platform- update/](https://tether.to/wallet-service-and-platform-update/) [1] [https://wallet.tether.to/transparency](https://wallet.tether.to/transparency)

</comment></comment></comment></comment><comment><USER10> @JulienHamilton (author at bottom of page), why would you share this with others? If arbitrage exists, there is not benefit to you allowing others to profit, as it eats into your profit. So what's the reasoning behind releasing this?

<comment><USER11> You're right in theory, but that's only really a risk if it actually works, which this doesn't.

Also, if the author is interested in increasing market efficiency, but not in exposing themselves to the risk of being caught in a halfway position when an exchange breaks, it makes sense to release as FOSS. The target users would then be the exchanges themselves.

</comment></comment><comment><USER12> Two words: "counterparty risk".

<comment><USER13> I'm surprised this comment isn't #1!

<comment><USER12> I probably should have added an explanation for those unfamiliar with the term, but then it wouldn't have been two words! :)

Essentially conterparty risk is the risk that the other party to a contract, in this case the broker, defaults.

Bacause automated arbitrage trading requires you to hold your funds with the broker, rather than transferring them to your own (preferably cold) wallet, you are exposed to the risk that the broker goes out of business without returning your funds, or otherwise fails to live up to its side of the bargain.

With crypto-currency exchanges, that risk over the long term might be assessed to outweigh the possible rewards from arbitrage trading.

<comment><USER14> This. I wrote a crypto arb bot in 2014 and decided to stop working on it / open-source it for the same reason after a couple exchanges that I had cryptos in mysteriously vanished.

</comment></comment></comment></comment><comment><USER15> "The Bitcoin market could suddenly lose twice its value that this won't make any difference in the strategy returns."

Just FYI I think you mean 'lose half its value'. I doubt we're going to see BTC go negative.

<comment><USER16> All right settle down

</comment></comment><comment><USER17> From the README:

      >> your maximum loss on an exchange won't be
      >> greater than $xx no matter what.

Unless I'm misunderstanding; the bot sells short on one exchange and buys on the other. If there was a bug where it didn't cover the short sale with a long buy, and Bitcoin price goes up, you'd be liable for the increase in price.

<comment><USER17> And here's an instance of this very bug! [https://github.com/butor/blackbird/issues/348](https://github.com/butor/blackbird/issues/348)

<comment><USER18> And they will always happen - once you send a first transaction of the pair, if anything goes wrong (eg. overloaded exchange timeouts on API call) with the second one, there is no undo.

</comment></comment></comment><comment><USER19> Note that unlike most other arbitrage, this isn't foolproof. High volatility can kill it, and price differences on some exchanges only exist due to geographical or technical restrictions (so the price is always a few dollars higher/lower). Definitely a fun experiment, but don't expect it to make you a lot of money.

</comment><comment><USER20> It's worth reading the linked issue for a refresher on how arbitrage, and this scheme in particular, work: [https://github.com/butor/blackbird/issues/100](https://github.com/butor/blackbird/issues/100).

I think the pathalogicial case is if the markets never converge significantly, or more likely diverge wildly, e.g. one gets hacked. Otherwise, Blackbird will wait it out until it hits a pre-determined settable profit margin.

I'm guessing plausible return rates are low, but with the relative safety you can risk a bit more than just "crystal-ball"ing the market or playing daily lows and highs.

</comment><comment><USER21> previous discussion: [https://news.ycombinator.com/item?id=13889608](https://news.ycombinator.com/item?id=13889608)

</comment><comment><USER22> The issue is BTC trading costs are so high that arb'ing it doesn't work well. You need massive spreads and perfect trading execution for this to work.

<comment><USER23> Since when is a trading cost of 0% (maker, high volume, bitfinex) and 0.1% (taker, high volume, bitfinex) so high?

</comment></comment><comment><USER24> "Information arbitrage" will become more important with crypto: "Contagious Speculation and a Cure for Cancer: A Non-Event that Made Stock Prices Soar," with Tomer Regev, Journal of Finance, February 2001, Vol. 56, No.1, pp. 387-396.

[https://www0.gsb.columbia.edu/faculty/ghuberman/research.htm...](https://www0.gsb.columbia.edu/faculty/ghuberman/research.html)

</comment><comment><USER25> BTC arbitrage is very risky due to transaction times, volatility, and volume. And it's often not worth it depending on your region due to potentially high fees. It's not something I would recommend to people who have never done it before.

As an experiement, go on to a site like CoinMarketCap. Click on BTC->Markets. Sort by price. It looks like a _ton_ of arbitrage opportunities, right? Well... now try to take advantage of it.

<comment><USER26> The OP claims their system isn't affected by transfer times. Read it and tell us what you think.

<comment><USER27> Of course it's affected by transfer times, it just takes some thought to understand why. Ultimately, in order for this to close out the position for a profit, the prices have to converge for long enough, and in order for that to happen reliably someone has to do arbitrage the slow way by transferring money. While you're waiting for that to happen, you're paying interest on the short position and exposed to the risk of a price increase causing a margin call that liquidates your short at a loss. The amount of profit you can make is also limited by the time it takes for the prices to converge.

<comment><USER28> it does not work like that, it requires you to have "money" or the ability to short/long at all exchanges and then u simply buy/sell locally.

</comment></comment></comment></comment><comment><USER29> Given how slow BTC transfers are now (can be 1+ day out of gdax), you would need to keep sizable amounts of BTC on each exchange and rebalance periodically.

While technically opportunities exist daily (compare the huge difference in prices this moment at [https://coinmarketcap.com/currencies/bitcoin/#markets](https://coinmarketcap.com/currencies/bitcoin/#markets)) but tough to execute due to BTC transfers or fiat transfers being high- friction.

<comment><USER30> I just tried to do this last week.

The issue I ran into is you can't move dollars between exchanges easily, so to rebalance, you've got to switch to something else. So you're profiting from volatility on one side and then betting on it not happening when you rebalance... and for the rebalancing, you have to wait a lot longer (as compared to trading instantly between currencies on the same exchange).

The other issue is that you have to anchor to something, and you can't anchor to the USD generally because even dollars in various exchanges aren't effectively worth the same amount (since you can't get them out as quickly / easily / risklessly in all exchanges). So you've basically got to anchor to US dollars on a certain exchange, and make trades based on the value of, for example, "Litecoin if sold on GDAX." That adds complexity, but might just be the reality of arbitrage.

That and I'm not sure the order books were large enough to make anything other than small amounts of money. The "last sell" price is just that--the price it last sold for. It doesn't take a whole lot of money before you've driven the price toward parity (and your arbitrage opportunity away).

Anyway--for me it was just a winter vacation project more for the experience than expecting real success. And it may actually work better on a week that wasn't last week (which was a bit uncommon). I guess we'll see.

</comment></comment><comment><USER31> can someone explain this app in laymen's terms? is it an automatic sausage maker? or a slot machine?

<comment><USER19> Arbitrage:

Person A is selling apples for $5 and buying for $4.50.

Person B is selling apples for $4 and buying for $3.50.

You buy apples from person B and sell to person A. Of course, this is a bit oversimplified- this project uses a few tricks to get around volatility.

</comment></comment><comment><USER32> And the more people that run this, the more efficient crypto markets will be! It's a win-win.

</comment><comment><USER33> I find it odd that Bittrex isn't even mentioned as one of the potential exchanges. I've found them to be more stable and user-friendly than other exchanges.

<comment><USER34> There was a few users on reddit recently that claimed to have gotten robbed by Bittrex, not sure if it has anything to do with it: [https://www.reddit.com/r/CryptoCurrency/comments/7lfhfu/bitt...](https://www.reddit.com/r/CryptoCurrency/comments/7lfhfu/bittrex_stolen_my_money_too_its_far_worse_333230/)

</comment></comment><comment><USER35> I didn't read this, but think about it: if someone knew how to arbitrage BTC, or anything, why would they share it?

</comment><comment><USER36> Or: just invest a bit at a time in [https://finance.yahoo.com/quote/VTSAX/](https://finance.yahoo.com/quote/VTSAX/) and forget about Bitcoin. Concentrate on advancing your own skills and career, and maybe invest in some local real estate if you have some extra cash.

<comment><USER37> Or do both. Diversification across asset classes is good.

<comment><USER36> VTSAX has a lot of diversification built into it, and most importantly, has extremely low fees. Get some bonds if you'd like too.

<comment><USER37> Thanks, but I already know, I've been investing in it for over 10 years! It's done very well. I also have some BTC and ETH.

</comment></comment></comment></comment><comment><USER38> Wait, since when does GDAX allow short-selling?

</comment><comment><USER39> Last time I checked they were using floating points to represent monetary values. I would not trust this piece of software regardless of how clever their strategy may be.

<comment><USER40> The whole "never use floats as money" thing is a little overblown. If you need exact values, where everything needs to add up in the end, sure. But if you're generating the value yourself it doesn't really need to be precise. For example - create a sell order for ten percent less than the current price - that doesn't need to be exact.

</comment></comment><comment><USER41> I will tell you that any working piece of code that allows someone to make money, is not public. Use this if you want to inevitably lose money.

<comment><USER42> That seems like a silly statement to me. Obviously, huge amounts of code that "allows someone to make money" is available publicly, for some definition of "making money" or other. I am guessing your statement is specifically directed towards code that is meant for trading markets and referring to the efficient market hypothesis. That may or may not be true but I think it would suit you to at least back up such a claim, especially when it comes to crypto currencies which are obviously a very immature asset class.

<comment><USER26> Yea he means trading systems. There are thousands of people selling "trading systems" for the stock market, by definition none of them work.

An example is why Warren Buffett got special permission from SEC to withhold reporting his trades for longer periods then normal. If you know that WEB bought a stock today, then you know he's done the research and it's a clearly profitable trade to buy and hold it for the long run. If WEB had to report trades daily, he'd be out of business, he'd never be able to buy more than a tiny amount of a stock in a single day, because the next day its price would have increased at least 20%.

Selling any kind of successful trading system is to invite others into your trades and make them less profitable for you. Selling the system only makes sense if the system is unprofitable or it's so thinly profitable that selling it to suckers is more profitable.

<comment><USER43> If the price of the stock would increase tomorrow by 20%, why wouldn't he be able to buy more than a tiny amount today?

<comment><USER26> Warren has over $100B invested in public equities (stocks). He's s believer in concentrated portfolios, ie he doesn't want to own more than a few stocks st a time. If he can't buy $10B worth of a stock he's not interested.

There isn't a stock in the world you can buy even $1B of in a day without driving it's price up dramatically yourself. So Buffett has to slowly accumulate a position over weeks and months.

<comment><USER43> Oh right, thanks for the explanation.

</comment></comment></comment></comment></comment></comment><comment><USER44> Anyone actually using this? I've looked at it recently, but not sure how well it works.

<comment><USER19> I used it late 2015 and it was working okay (still lost money sometimes, ended up with a very tiny gain). It doesn't work very well anymore, mostly due to Bitfinex being the only short exchange that's supported.

</comment></comment><comment><USER45> Amazing people are naive enough to post this kind of stuff publicly!

</comment><comment><USER46> I'm sad at the quality level of comments on this discussion. Lot of people are commenting clearly without reading EVEN the readme.md of the linked post.

This tool advantage relies on the fact that NO bitcoin needs to be moved, so all posts about long time of btc transfers make (almost) no sense.

On the other side only ONE (so far) person mentioned (importantly) that it works only on bitfinex, and even him didnt clearly wrote that this work ONLY if bitfinex has higher price than other exchange (reducing arbitrage opportunities by half), because you can short btc only on bitfinex.

Where is HN from 5 years ago? :(

<comment><USER47> Was HN ever a place to talk about financial speculation schemes?

If you want to talk about this stuff, you want a forum full of financial trader people, not engineers.

<comment><USER48> Yes it was. It was much more business oriented than it is now.

</comment></comment></comment><comment><USER49> Seems like majority of HN hates crypto which is disappointing. Luckily there are a ton of great subreddits, slack, telegram, and discord channels out there.

<comment><USER50> Would you mind posting those?

<comment><USER51> I just started a Telegram group up recently for people casually interested in altcoins/trading. Welcome to anyone - [https://t.me/tradetradetrade](https://t.me/tradetradetrade)

</comment></comment></comment><comment><USER52> How to add a new exchange to this? Which interface need to be implemented?

</comment><comment><USER53> Why not run arbitrage on ETH etc. which have far shorter transaction time than BTC. That surely is a much safer bet with essentially the same API. With the current transaction time BTC arbitrage doesn't seem to be a wise idea at all. In between the several hours the price could have easily changed more than 10%.

<comment><USER19> This doesn't actually ever send coins over the network. It shorts on one exchange and goes long on the other.

 _As such it is market neutral (since prices should converge) and transaction time doesn 't matter.

_Still doesn't work too well.

<comment><USER54> In particular "prices should converge" is hiding a pretty big precondition in very few words. You don't only need prices to converge, but you need them to converge within a reasonable time span, which is obviously not guaranteed. (because if the market was efficient already then the prices would have converged already and it would not be feasible to run arbitrages like this)

<comment><USER55> It's the other way around... market efficiency is caused by things like this (not only arbitrage, but that's one important factor).</comment></comment></comment></comment>


Why schools are structured the way they are - <AUTHOR> https://www.vox.com/identities/2017/10/26/16533878/race-education-segregation-nikole-hannah-jones <comment><AUTHOR> The original title is IMO needlessly inflammatory, but the underlying material is interesting and useful.</comment>