Stable diffusion uses an open dataset (latest being LAION-5B I believe) so perhaps it's just the easiest to prove which images were definitely used in the training?

Then once the fight is rolling against one adversary, it seems intuitive to me other groups would pile on to increase odds of success.

So, perhaps it is just a matter of time until all of these major AI working groups are targeted this way, depending on how these cases shake out.