Legal shenanigans around the public domain. My understanding of the law here is that companies are under no obligation to provide public domain works that they have copies of, but that anyone who obtains such a copy can redistribute it. I don't know how the law works with "intent to distribute" as in the original case, but in this case I suspect he'd be ok since he was careful to take only public domain works. Unless he violated a hacking law somehow (unlikely, given the fairly trivial things that were required in the first attack), or ran afoul of the contract (very likely, given the all-encompassing nature of most click-through agreements these days).

It would be interesting to try to quantify quite how many public domain works are locked up inside paywalls. Easier to come up with a number of works than with a valuation on their economic value.