According to GOOD, more than half a billion people were unfriended on Facebook in 2011, up from 158 million in 2009. That’s what happens when you go to college and pretend as if you’ll continue any sort of correspondence with someone you’ve only ever spoken to once for five minutes, drunkenly at night. And then you graduate and realize you don’t even remember those people, let alone that night.

Industry experts, such as Morley Winograd, director of the Institute of Communication Tech Management at USC, think most of the unfriending comes down to people getting older and more privacy-conscious. Hence, users look to restrict access to their profiles only to people whom they know very well. Others believe the phenomenon is the result of users not interacting with Facebook as a social network, but more so as a repository simply for personal info. Neither of which does Facebook and its hunt for those coveted ad dollars any good.

[via GOOD]