This is indeed a new and bad situation, and I agree with Klaus; it's not Art, but just Easy Play, IMO. Very hard to combat, especially with good-resolution images being put on the web. I am always a bit reluctant about spreading my (better or commissioned) work without a watermark, but a watermark is of course ugly. And pieces may be cut out to be used.
The same is true for texts; AI seems to be able to produce really good 'stolen and combined' texts on an input sentence. So, for students it's real easy to 'write' their essays, get good marks and their graduation. But then? Same as with AI art, what kind of person are you then? Can you really make something? Can you succesfully work by yourself?
Interesting discussion, no doubt, but a future I somehow fear.