When I updated my iPhone to iOS 6, for some strange reason, all my Facebook contacts were added to my iPhone address book.
Did I want THAT?
So I took to twitter to see what people were saying.
They were not happy.
I'm glad some people can find the humor in this. ;-)
So I enabled Facebook, then went into the settings and shut off Contacts and calendar connect.
I think it undid the damage.
Let me know if it works for you, or if there's a better way to get rid of all these unwanted contacts.
Note: Someone told me to uncheck the Facebook group in my address book on my iPhone. I didn't have one of those.