...I told you so, in my entire life:
IS FACEBOOK DOOMED? Possibly. In the last week or two, several people I know — all of them attractive women between their teens and early thirties — have quit Facebook. Their biggest complaint is the lack of privacy, and its tendency to attract creeps. Under not just one, but two of Kaus’s Rules Of Punditry (“generalize from your own experience,” and “three events make a trend”) this now represents a legitimate phenomenon.
It helps you keep in touch with people you don't want to keep in touch with, ie creeps.