Let's say you have some of your art up on the internet, in places like DevianArt and Elfwood. One day, a friend of yours sends you a link to a YouTube video in which someone has used some of your art (a particularly old and crappy sample of it that you never liked anyway) without asking or crediting you.
What would you do?
I ask because this just happened to me, and I'm a bit agog at the fact that someone thought my crappy doodle from my Junior Year of highschool was good enough to steal. Well, maybe not "steal," so much... but you get what I mean.