[Bjorkbat]

Fair point, we use metaphor to explain and understand a variety of topics, and a lot of those metaphors are best understood through pop culture analogies.

A reasonable compromise then is that you can train an AI on Wikipedia, more-or-less. An AI trained this way will have a robust understanding of Superman, enough that it can communicate through metaphor, but it won't have the training data necessary to create a ton of infringing content about Superman (well, it won't be able to create good infringing content anyway. It'll probably have access to a lot of plot summaries but nothing that would help it make a particularly interesting Superman comic or video).

To me it seems like encyclopedias use copyrighted pop culture in a way that constitutes fair use, and so training on them seems fine as long as they consent to it.