Tineye is a pretty darn good tool, first I have heard about it.
I use to just google search my images.
My first one to ever be taken (3 times by the same guy) was a random pic of my daughter.
I contacted the Admin to the site the user was posting on 3 times and each time the member was banned and the photo removed but he would come back with a slightly different name and post again.
Some people just dont learn.
My latest one was an HDR of my Mustang in a parking garage.
An automotive detail shop used the photo on their business car.