Unless it's a difamatory or offensive use you shouldn't let all this buid up...
Your image is probably on a bunch of other servers than yours (i.e. google cache.), you posted it..someone saw it and posted it elsewhere while crediting you...Was there something offensive about the post? was it a comercial use?...because if there wasn't you shouldn't worry (you will live way better if you don't let other people's actions bother you so much).
Maybe i have a different way of thinking but i would never mind all of that unless the usage was denigrant...Culture evolves by the sharing and use of information, one of the best things that has happened to music and it's growth and democratization was the ability to use samples to create new sounds and tunes.
Be happy that you reached out.
Oh, and legal action or professional counsel will cost a lot (i just payed half a 8-16 with the fee of a report i made...if i have to go to trial for this case i may be able to join the k5 ranks...and that considering that it will not last much since the matter is pretty clear...soo i would say that in your case, if it was me deciding, the hassle would probably steer me out of those warpaths).
Last edited by Coeurdechene; 04-18-2011 at 08:15 AM.