Title: Usage of 能骗就骗 (if you can cheat, then cheat)
Tags: usage;expressions;idioms
Question: There is a Youtube video by a popular Youtube blogger who lives in China and is married to a Chinese woman, and he says in that video that the Chinese language has the idiom 能骗就骗 ("if you can cheat, then cheat"). The blogger explicitly calls this phrase by the word "idiom." Here is the link that brings you to the corresponding moment of that Youtube video: Link. The video is quite popular and has almost 3 million views and 40+ thousand likes.
I talked with a few native Chinese speakers about that phrase and got conflicting opinions about its role in the Chinese language. Two people said that depending on the situation, this phrase is used in two different ways - as a negative characteristic (e.g., "he is such a hardcore cheater and scammer that he will ruthlessly cheat whenever he can and no matter what") or as an encouragement to cheat a bit where it is relatively appropriate (e.g., "just cheat on your school test if you can" or "just cheat a bit on your taxes if it is safe to do so"). Another native speaker said that he had never seen this phrase being used in the second way and that the phrase is simply a name for cheaters. Another Chinese said that this is not an idiom, but rather merely a grammatically correct phrase.
In an attempt to find out the truth about that phrase, I decided to ask here.
Please note that I am not going to make any negative judgement about the Chinese or their culture based on the usage of this phrase, so please do not sugarcoat things. Every language has expressions of all kinds, and every nation consists of people of all kinds. For example, the English language has the idiomatic phrase "Never give a sucker an even break." This phrase means that one should take advantage of those who are not well informed if given the chance. The German language has the idiom "Der Ehrliche ist immer der Dumme" ("the honest one will always turn out to be the dumb one"). The Russian language has the idiom "Не наебешь - не прoживешь" ("if you don't f*ck people over, you won't survive"). Everyone chooses his own strategy and principles. So my question is purely linguistic and is purely about that the use of 能骗就骗 from the linguistic standpoint.
My question is this: Is the phrase 能骗就骗 idiomatic or just a random grammatically correct phrase, and how is this phrase used in the Chinese language? In particular, is it sometimes used as an encouragement to trick or cheat? Any examples are very welcome.
Comment: I have no memory hearing people using this phrase.

Comment: `能騙就騙` is more like a common usage of the sentence pattern `能__就__`. Other common usages of this sentence pattern: `能不做就不做`, `能裝死就裝死`, `能開開心心的就開開心心的`, `能活著就活著`, `能吃就吃`, `能喝就喝`, `能睡就睡`, `能拒絕就拒絕`.

Comment: 能吃就吃: 如果你能吃, 那你就 **尽量** / **尽可能** 的吃, 能做就做: 如果这件事能做, 那你就 **尽量** / **尽可能** 的做.

Comment: 这件事我能不做就不做: 这件事如果我可以不做, 那我就不去做.

Here is the accepted answer: 能骗就骗 is a direct translation from a Cantonese expression "呃得就呃" (scam just because you can/ scam whenever you can)
It is a negative remark on someone's behavior; There's no encouragement of swindling
Example sentence:
"戴條手鍊可以防癌? 仲要賣成千蚊? 唔好呃得就呃噃!" (Wearing a bracelet can prevent cancer? And it costs a thousand dollar? Don't scam people just because you can)
"條友呃得就呃, 千祈咪上當!" (this guy scam people whenever he can, don't fall for it)
呃得就呃 is commonly used in Cantonese, but 能骗就骗 may not be as popular in Mandarin
As  AnnieFromTaiwan pointed out 能X就X is a common sentence pattern, so is X得就X in Cantonese. However, the instances you can apply "呃得就呃" to are so numerous, it stands out among all other similarly structured phrases and has became a 'common expression'
Comment for this answer: Donald Trump is a prime example of someone who 呃得就呃*

Here is another answer: In Mandarin, it is just a random grammatically correct phrase, not an idiom. But as Tang Ho pointed out, it might be popular in Cantonese.

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