But how smart is this, really? Who's going to steal your 750 x 500 pixel image and use it for anything that they should have paid you for? Who makes any money by doing that? (Perhaps porn mavens, I don't know—then again, I doubt those types would be punctilious about the niceties of copyright.)
You just can't do all that much with a 750-pixel-wide JPEG. And, as I'm sure you've noticed, there are rather a lot of them on the World Wide Web.
What I would have done with the picture, of course, is to introduce it to a whole new audience and then link to the rest of the guy's work. I don't know if being seen by, I don't know, maybe thirty or forty thousand sets of eyes on TOP over the next week or two would have sold any prints for the guy. But it probably couldn't hurt. Again and again I get notes from people to whom we've linked telling me that we spiked their hit count big time.
Copyright may be important for the big shots whose work is in tremendous demand. But I suspect it just helps small fry remain obscure.
I might be wrong about this. (Again: Oh well.) My advice, though: If you're worried enough about your little JPEGs to attach copytight notices to them, make sure you also put your contact information somewhere nearby, so people like me can get in touch with you if they want to threaten your rights with some valuable free publicity.