> registered before one can sue for infringement.
It's a little unclear quite what it means for a work to be protected if you don't actually have any recourse when infringement occurs.
> Title 17 U. S. C. §411(a) states that “no civil action for infringement of the copyright in any United States work shall be instituted until ... registration of the copyright claim has been made in accordance with this title.”
> ... however, a copyright owner can recover for infringement that occurred both before and after registration
Far more then that, it's an absolute show-stopper for any potential lawsuits, as it's really unlikely any potential litigant will be able to prove that even a large majority of the images have been registered, and thus eligible for a lawsuit.
Well, with the registration issue. They still have to prove us of an exclusive right and overcome any argument that the other side puts up that the use involved fell under fair use, but they'll have dealt with the threshold issue of “are we allowed to sue over the works we are alleging were used".
Based on what legal reasoning?
You need to register prior to bringing a claim. That isn't a big deal and can be done easily after any alleged infringement. But to get the attorney fees you need to have registered before the infringement occurred, something you cannot fix after you decision to sue.
Then to split hairs yet again, was the work registered at the time it was copied by the AI, or are you suing over infringement that occurred after a late registration? Are you claiming it was registered when the AI was trained on it, or are you claiming registration during the work's subsequent use by the AI after the training process? Maybe you can get attorney fees despite late registration if you can prove ongoing infringement after the pre-registration training process.
The issue here is that the artists are making broad claims that DeviantArt infringed all of their works (by letting them be used as training data), even though they didn't register all of their works. Only some of the artists that are suing registered their works, and they may not have registered all of the works they are suing over. That's what the first sentence in the next paragraph is about: "[E]ven if plaintiffs narrow their allegations to limit them to Output Images that draw upon Training Images based upon copyrighted images..." The judge didn't misspeak here.