Comment by davidcbc
Even assuming you are correct, which I'm skeptical of, does this make it better?
It's essentially the same thing, they are copying from a source that is violating copyright, whether that's a pirated book directly or a pirated book via fanficton.
Generally I think it matters a great deal to get the facts right when discussing something with nuance.
Is this specific fact required to make my beliefs consistent... Yes I think it is, but if you disagree with me in other ways it might not be important to your beliefs.
Legally (note: not a lawyer) I'm generally of the opinion that
A) Torrenting these books was probably copyright infringement on Meta's part. They should have done so legally by scanning lawfully acquired copies like Google did with Google Books.
B) Everything else here that Meta did falls under the fair use and de minimis exceptions to copyrights prohibition on copying copyrighted works without a license.
And if it was copying significant amounts of a work that appeared only once in its training set into the model the de minimis argument would fall apart.
Morally I'm of the opinion that copyright law's prohibition on deeply interacting with our cultural artifacts by creating derivative works is incredibly unfair and bad for society. This extends to a belief that the communities that do this should not be excluded from technological developments because there entire existence is unjustly outlawed.
Incidentally I don't believe that browsing a site that complies with the DMCA and viewing what it lawfully serves you constitutes piracy, so I can't agree with your characterization of events either. The fanfiction was not pirated just because it was likely unlawful to produce in the US.