I Googled my comic the other day and found a rather suspicious website called Free-Stock Illustrations (I'm not going to link it as it could possibly contain malware) that had one of my comic pages as a free stock image!
They only have two ways to contact them (through a 'Contact us' and a 'Report Image' link) and they both state that they will ignore copyright claims unless a form is filled in. Of course, there is no form to be seen anywhere on the website.
I looked them up and, at least the domain, is based in the Bahamas.
Hooray for tropical art theft I guess....