Because in all those cases the person who knows the material is copyrighted has an incentive to tell people (so they can get paid). In this case the opposite i

Because in all those cases the person who knows the material is copyrighted has an incentive to tell people (so they can get paid). In this case the opposite it true: the only person who knows an image was AI generated will have an incentive to keep quiet. And even if that is not the case, how much of the media you consume comes from "professional media" vs Reddit, Facebook, Instagram etc? I watch maybe 10min of TV/Movies per day on average, I spend maybe 1h on reddit alone... Also, FYI, News outlets are not restricted by copyright.