the art of friendster pictures and authentication
So here we are in the age of social networking, and we're all publishing profiles of ourselves (say, on Friendster or wherever) that give complete strangers a pretty good idea of our likes, dislikes, habits, friends, etc. Talk about stalker-bait. So people use pseudonyms and obfuscation to keep their Internet stalkers and their real-world stalkers separate.
But people still want their friends to be able to recognize them. Some include pictures in their profile that only show a bit of themselves. The pics give enough detail that friends know who it is, but everyone else just sees an almost random image. It's a sort of authentication, but targeted at a very specific set of people: those who know us well in real life.
As we contemplate publishing even more information about ourselves (e.g. location awareness), we're either going to have to give up on keeping our various identities (real and Internet, business and personal) separate, or else social networking services are going to have to provide a more general, effective way of managing our identities than authentication-by-picture.