I think that for the most part, artists don't really have a problem with it. I did, however, have one artist whose shop didn't contain *any* copyrighted images on their walls. He told me that for him, it wouldn't be worth the hassle if someone came in with copyright issues. He went on to say, though, that if someone came to him with an image that they brought from home, he wouldn't have a problem tattooing it on for them.