trying to step back and be super objective here.
If I buy a book and read it and learn from it, my knowledge isn't 'derivative'.
If I steal that book, I still get to keep my knowledge of it, I just have to pay a fine or jail for the theft.
So 82TB of books should be broken down into a simple spreadsheet of each book, it's label price, and the penalty for theft and Meta should be charged for that amount. You can't throw meta in jail, maybe you could throw the person who downloaded things in but they were an agent of meta so that's murky. The fines should be basically statutory maximums since the jail time isn't super practical.
They could have just bought all these ebooks off Amazon and had fair-use rights to it so the crime here isn't the use of the books, it's the theft of the books.