[gruez]

That's irrelevant on two counts:

1. Not all LLMs were trained on illegally obtained books, and there's at least one court case where the use of illegal obtained books has been ruled illegal (exact sanctions are TBD)

2. In the context of discussing LLMs or students illegally distributing books, whether they obtained it legally is irrelevant. If you bought a book legally, that still doesn't give you the right to photocopy it and send to your friends.