I found several of my images on this page: http://myazdatabaseimages.org/fractal+tree+design
Although they give a link back to the original as the source image, a large thumbnail can be downloaded from their site. Jay has just finished securing our large thumbnails from download, so this site is redistributing.
You may be happy to have your images on there. I am not, and I have had to systematically report each individual image.
These are the first I found, during a Google search. I believe they are very likely to have more, and not just of mine. If you are concerned, I suggest you search for your own.