“Stable Diffusion contains unauthorized copies of millions—and possibly billions—of copyrighted images.” That’s going to be hard to argue. Where are the copies? “Having copied the five billion images—without the consent of the original artists—Stable Diffusion relies on a mathematical process called diffusion to store compressed copies of these training images, which in turn are recombine…
One idea I had was to try to recreate the original using a prompt. If you succeed, it should be obvious that the original was in the training set?
"The Night Watch, a painting made by Rembrandt in 1642"
It generates a convincing low-res imitation about half the time, but it also has a tendency to make the triband flag into an American flag, or put an old ship in the background, or replace the dark city arch with a sunset...
If you keep refining the prompt, you can get closer, but at that point you're just describing what the painting should look like, rather than asking the model to recall an original work.