> Laws have to be enforceable.

This is a good point. In this case, it does seem pretty easy to enforce, though - just require anyone hosting an LLM for others to use to have full provenance of all of the data that they trained that LLM on. Wouldn't that solve the problem fairly easily? It's not like LLM training can be done in your garage (at which point this requirement would kill off hundreds/thousands of small LLM-training businesses that would hypothetically otherwise exist).