I personally disagree with the rulings thus far that AI training on copyrighted information is "fair use", not because it's not true for human training, but because I think that the laws were neither written nor wielded with anyone but humans in mind.

As a comment upstream a bit said, some people are now rethinking even releasing some material into the public, out of not wanting it to be trained by AI. Prior to a couple of years or so ago, nearly nobody was even remotely thinking about that; we could have decades of copyrighted material out there that, had the authors understood present-day AI, they wouldn't have even released it.