I worked on an extremely niche project revolving around an old DOS game. Code I worked on is often pretty much the only reference for some things.

It's trivially easy to get claude to scrape that and regurgitate it under any requested licence (some variable names changes, but exactly the same structure - though it got one of the lookup tables wrong, which is one of the few things you could argue aren't copyrighted there).

It'll even cheerfully tell you it's fetching the repository while "thinking". And it's clearly already in the training data - you can get it to detail specifics even disallowing that.

If I referenced copywritten code we didn't have the license for (as is the case for copyleft licenses if you don't follow the restrictions) while employed as a software engineer I'd be fired pretty quick from any corporation. And rightfully so.

People seem to have a strange idea with AI that "copyleft" code is free game to unilaterally re-license. Try doing that with leaked Microsoft code - you're breaking copyright just as much there, but a lot of people seem to perceive it very differently - and not just because of risk of enforcement but in moralizing about it too.