I use Google image search all the time and have never had that happen.
The protection is most won't bother lifting it if the copyright/watermark is right over the image. I don't use a watermark, just my name usually and hope that most find it too bothersome to want to crop it out to use my images. Doesn't always work though, I used to find them on eBay all the time. I always sent them a message with a copy of the eBay photo copying rules, that usually does the trick, they don't want me to report them.
