"... in what way do they verify that people are who they claim to be? ..." The authentication isn't perfect but it's contained in the social graph itself. My u

"... in what way do they verify that people are who they claim to be? ..." The authentication isn't perfect but it's contained in the social graph itself. My use case is not normal but is in keeping with the original intent of Fb of only friending those you actually know and meet. With the exception of 1 or 2 persons, every one on my contact list is someone I've know for a long time. It's not foolproof, but you can validate people by who they are connected to, assuming they are RW connections not OL connections. Real people tend not to friend, non people.