Originally Posted by Tuco
Which is also what makes most of the complaints about "violating copyright" dodgy at best.
It will be hard to prove in a courtroom when the "copy" of your work is factually different from the original, given that you can't register/copyright a style.
If these AI companies are going to lose the legal battle, it will be all about the jury questioning their right to access the "training data" and not about the results being something "stolen".
Speaking with all the experience from watching a single youtube video essay, there seems to be precedence for copyrighting a style. One of the most popular cases was the battle between Pharrell Williams' "Blurred Lines" and Marvin Gayes' "Got to Give It Up," where Blurred Lines was accused and found guilty of of copying the style or feel of Got to Give It Up, even though the [chords, rhythm, etc] weren't the same.

I have absolutely no idea how/if this applies to the art world, or if the only difference is that the music industry is overwhelmingly more regulated by big corporations with vast monetary incentives to protect their copyrights and access to lawyers...

Originally Posted by Tuco
There's also the other side of the coin, which is that even conceding that AI companies will have to compensate artists, it's hard to imagine the "quantification" of that compensation being anything but pitiful.
If your "stolen work" amounts to nothing more than one part in a billion of a dataset used for training the software, what sort of compensation per use should you really expect?
Even if an AI company only has to pay each artist a fraction of a cent, that times X-billion images can add up to large sums. Correspondingly, fractions of a cent paid to an artist multiplied by "Y images produced by all AI companies" can also add up.

For your other questions, I suppose in general my response is "human effort to create art should be appropriately compensated, and mass-produced AI images require ~no human artistic effort (obviously the programmers of the AI put in work)" Thus, e.g., a fan artist should be given much more leeway than a company using an AI art generator.