Mis-tagging would also bite them in the backside by making it harder for their own fans to find their work. And what school or library or workplace would allow access to Big Name Artist Joe Whomever's website once it gets known for having "big boobs" or "sexy babe" or other NSWF tagged images? I do agree that anyone who does not want their work used in AI training should be able to say no and have it removed, or compensated/licensed if they agree, but poisoning the well does no one any good, not even themselves.