Note to providers: if you watermark your photos with your NAME and PHONE NUMBER, they can't be stolen and used by other providers. (A watermark is a translucent layer on top of your image. It looks similar to the little logo in the lower right corner when you watch TV)

I did a quick Google search and found lots of cheap and free software to do this:

http://winwatermark.com/
http://shareme.com/showall/freeware/watermark.html
http://www.watermark-image.com/

Problem solved!

But unless your watermark spans the body of the pic, they simply crop the pic and steal it anyway.  Good idea though!  It just requires that the watermark is in an area where it cannot be cropped out of the pic.