> I don’t believe any of these companies have paid for all the books they have trained on.

Did you miss the "book burning" hysteria from a couple weeks ago? These companies have been trying to digitize copyrighted materials legally, in which copyright law demands destruction of the original, and people shit on them even harder.

It's clearly not a problem for these companies to buy the books they need for training, and they have been doing that in crazy high volumes. Lots of good training materials simply cannot be legally purchased though, and should those parts of human knowledge just be ignored?