It's likely already trained on Windows source code unless they have specifically excluded the repositories of the leaked Win 2000 code. Perhaps someone who's never going to contribute to ReactOS and Wine can verify?

Why would they do that, regardless of whether the output could be restricted via Copyright or not? Also, this case isn't about copyright, as the lawyer clearly explains.

I was more talking about the general morality issue than the specifics of the case.

Why wouldn't they? They are both large important codebases which they can do whatever they like with. If they are confident that Copilot does is akin to learning or at least something transformative then it makes perfect sense.

The output isn't guaranteed to be free of copyright from its training materials. It just usually is. There have been clear demonstrations of it regurgitating code from the training set verbatim, which would of course still be covered by the original license.

Microsoft isn't going to train Copilot on Windows code for the same reason it didn't train it on private repos: the code is private and they don't want to risk leaking private code.

I imagine there would be no problem training it on e.g. the Unreal Engine code which is not open source but is available to read.

The big practical issue is that there's no warning when Copilot produces code that might violate copyright, so you're taking a bit of a risk if you use it to generate huge chunks of code as-is. I imagine they are working on a solution to that though. It's not difficult conceptually.

Private isn't a useful distinction though right? Even open source code often has a licence and conditions on how you can reuse or integrate it into your own code. Someone owns it.

If you sell a product which can regurgitate large parts of code who's licence doesn't allow it to be completely freely used and modified then this kind of outcome seems a foregone conclusion.

> Private isn't a useful distinction though right?

Yes it is. If code is public you can't necessarily use or copy the code (depending on the license) but there's nothing stopping you reading it and learning how it works and any secrets contained in it (e.g. information about future products).

There's a reason most proprietary software isn't "source available".

> If you sell a product which can regurgitate large parts of code who's licence doesn't allow it to be completely freely used and modified

Yes but they don't do that. I'm not sure why people are finding this so hard to understand.