I use tineye once just for the hell of it. Someone I was chatting with through on the other side. Turns out it was a stock photo used in a bunch of men's health adverts. Let's just say when I called him on it, he no longer wanted to meet me and had "met" someone else within 2 days. [:D]
I just open Google images in one tab, then view the image I want to search so it's on its own page, then drag it to the search box on the Google images page and voila. They will also show "similar" images and some of them can be pretty funny. :D
There is actually someone who has the same photo on their linkedin.com profile as on a profile here....and the linkedin.com site uses their real name. So for anyone who wishes to keep their real name separate from their collarme profile....well, it's best to use a different photo. ;)
I don't use my full name anywhere. It's either the initial of my last name or none if it's not a mandatory field. That goes for all my social network accounts. Don't put my address or my phone # either.