When you copy a file, it's trivially simple to prove it's a copy and not an original work.

How can one prove that X is a copy when none of the source code match original? Clean room re-implementations are not illegal after all, if we go that way (yeah, yeah, I know about clean room argument).

While I personally do not think it would be different, but a lot of LLM folks are, and even some companies (rushing to blatantly clone and de-compile stuff). Kinda strange feeling sitting and looking around in the midst of it, y'know.