There was a thread that was started here a few months ago but i can't find it. It was about a search engine where you upload your photos and it will search on the net to find photos similar to that you uploaded. Some photographers here even tried it and find some of their photos that were used illegaly on other websites.
I don't remember the name of the search engine (i think its FishEye but i'm not sure) or the webpage of that search engine. Could someone here please help?