It’s important in the fair use assessment to understand that the training itself is fair use, but the pirating of the books is the issue at hand here, and is what Anthropic “whoopsied” into in acquiring the training data.
Buying used copies of books, scanning them, and training on it is fine.
Rainbows End was prescient in many ways.
I could read a book, but its highly unlikely I could regurgitate it, much less months or years later. An LLM, however, can. While we can say "training is like reading", its also not like reading at all due to permanent perfect recall.
Not only does an LLM have perfect recall, it also has the ability to distribute plagiarized ideas at a scale no human can. There's a lot of questions to be answered about where fair use starts/ends for these LLM products.
Which is one fundamental things how copyright is handled. Copying in general or performing multiple times. So I can accept argument that training model onetime and then using singular instance of that model is analogues to human learning.
But when you get to running multiple copies of model, we are clearly past that.