> Nitpick: Fair use isn't an exemption from copyright, it's a defense for violating copyright)

Nitpick: Fair use is both a Constitutional and statutory (the latter codifying the former) limitation on the exclusive rights granted as part of copyright, so it's definitely an exception.

Procedurally, it operates as a defense, but that's not inconsistent with it being an exception.

True, the contrast here would be e.g. copyright law as usually found in EU states, where the are actual, enumerated lists of exceptions to copyright. Fair dealing as used by some former UK colonies seems more similar to the EU approach than US fair use doctrine.

"Training of ML models with data not licensed to you and then selling the output of the model" isn't on those lists, and consequently is a flagrant copyright violation in - broadly - the entire EU.

If you are a developer in the EU using Copilot, it is really pretty obvious that using Copilot is a commercialized copyright violation, which is e.g. in Germany (but I'm guessing many other states) a criminal offense, not a civil offense. Now, people might say, they're paying Microsoft for this service, and that's not in the EU, so something something can't prosecute. Of course, that doesn't actually work in the real world, and this corner of prosecuting copyright violations has been extremely well explored during the many, many trials of people committing IP violations of music and films over the past few decades.

In addition to that, I'm pretty sure routine copyright violations by an employed developer would be one of the more clear-cut reasons for a termination without notice and compensation for having to replace the affected code.

> True, the contrast here would be e.g. copyright law as usually found in EU states, where the are actual, enumerated lists of exceptions to copyright.

How is that a contrast? The US has an actual, enumerated list of exceptions (the US term is “limitations on exclusive rights”, of which fair use is, in the US Code order, the first.)

See the section headings in Title 17, Chapter 1: https://www.law.cornell.edu/uscode/text/17/chapter-1

Fair use itself is open-ended, and not enumerated. US law has fair use and other limitations. In contrast, EU law does not have open-ended limitations, but only the fixed, enumerated limitations. So I don't get your point here - US law leaves significant room for interpreting limitations on copyright via fair use. EU law doesn't.

> Fair use isn't an exemption from copyright, it's a defense for violating copyright

My uneducated brain cannot tell the practical difference between them, can you or anyone knowledgeable please explain like I'm 5?

They're not accurate. Or at least not accurate to most jurisdictions that've I've read up on (some countries might be set up that way but I wouldn't know which).

Take UK law, "fair dealing" (I believe it's written as) is specifically stated as "not infringing copyright". Which means it's an allowance or exception, depending on how you want to phrase it. It's not something that is technically in breach and then used as a defence in (for example) court. In fact I don't even know how that kind of law would work in practice.

However since fair use can be a little subjective at times that does mean people are often forced to defend their position that their usage of the source material fell under "fair dealing".

You shouldn’t be downvoted

Generally speaking, this sounds incredibly dangerous to me - if the courts retroactively decide it isn't fair use - companies who have used Copilot generated code in their closed source offerings could find themselves in hot water.