how would legislators know an answer to this. lawsuits provide a platform for discussion based on which a policy can emerge. Guessing wrong answer in form of legislation will be detrimental to the society.
Or,
It can say, if I can read it or watch it at a library, and the llm uses publicly accessible access methods, its not different then if a person had read and watched all those works and then made thoughts and determinations out of them.'
Obviously, there's some complexity in both of those arguments, and its hard to see what exactly is right, but making the rules we play by would be really helpful about now.
It's funny you say that lawsuits provide a platform for discussion that leads to policy because you're describing the legislative process. I will grant you that the structure of lawsuits and amicus briefs does lend itself to quality discussion about issues and I think the legislative process could do with a bit of that.