[OldHand2018]

The article contains a link to an Adobe blog that talks about fair use of copyrighted material.

It references the fair use doctrine in a way that is not fully analogous to this type of use and mentions the Google books case. It also mentions that this is not settled law. It's clear that the author wants it to be fair use, but that might cloud their analysis.

Keep in mind that Google was scanning books that the legitimate owner of the physical books gave them permission to scan. If I buy a book and want to use it to train my model, fair use says I am free to do so. If I grab an unauthorized torrent of a training set, itself containing images were not legitimately purchased or licensed, there is absolutely no case law that I know of that says it is ok. I have to spend my money on lawyers trying to argue that I'm in the clear with no guarantee of success.

Maybe I'm wrong - I'd love to hear a convincing argument to the contrary!