tineye didn't find any of mine online, although I know that they are spread far and wide, especially trough sites like tumblr.

Here's a photo of mine right at the top, just did a random search, there are loads of my photos in the pin-up category and such: http://www.tumblr.com/tagged/dead+barbie

I don't really mind that kind of viral sharing, especially when the signature stays intact.
I have yet to see any commercial exploitation, if I did, I would definitely call a lawyer and get my fee + suitable compensation.