We need a ruling that LLM generated code enters public domain automatically and can't be covered by any license.

It's more or less already the case though. Pure AI-generated works without human touches are not copyrightable.

We need it to be infecting the rest like GPL does.

You probably misunderstood how "infection" of GPL works. (which is very common)

If your close-sourced project uses some GPL code, it doesn't automatically put your whole project in public domain or under GPL. It just means you're infringing the right of the code author and they can sue you (for money and stopping using their code, not for making your whole project GPL).

In the simplest terms, GPL is:

    if codebase.is_gpl_compitable:
        gpl_code.give_permission(code_base)
    else if codebase.is_using(gpl_code):
        throw new COPYRIGHT_INFRINGEMENT // the copyright owner and the court deal with that with usual copyright laws
GPL can't do much more than that. A license over a piece of code cannot automatically change the copyright status of another piece of code. There simply isn't legal framework for that.

Similarly, AI code's copyleft status can't affect the rest of the codebase, unless we make new laws specifically saying that.

Also similarly, even if Github lost the class action, it will NOT automatically release the model behind GPL to the public. It will open the possibility for all the GPL repo authors to ask Microsoft for compensation for stealing their code.

But then we would need a way to prove that some code was LLM generated, right?

Like if I copy-paste GPL-licenced code, the way you realise that I copy-pasted it is because 1) you can see it and 2) the GPL-licenced code exists. But when code is LLM generated, it is "new". If I claim I wrote it, how would you oppose that?

Laws exist to protect those who make and have money. If trillions could be made harvesting your kids kidneys it would be legal.

It's done extrajudicially in warzones such as Palestine where hostages are returned from Israeli jails, with missing organs, dead or alive [0].

[0] https://factually.co/fact-checks/justice/evidence-investigat...