If you are a friend of someone, that someone can, without your approval, add you to any group that your friend is part of
. A group like NAMBLA, for instance.
There is something pathological about Facebook. Just like with the privacy features (or rather, lack of) that caused consternation earlier this year. The honchos at Facebook just can't control themselves. They've already got a huge customer base with tons of preference-information that advertisers love. So why the constant push, push, push to further entangle their user base with potentially harmful features?
Facebook is out of control.
NOTE: Use Facebook if you must, but treat it like a social gathering at work. Don't reveal anything deeply personal and absolutely do not let anybody be a friend unless it's one of your six closest real-life friends.
I deactivated my account in June. There's just something deeply weird about Facebook. It devalues actual friendship by creating an illusion of friendship among people who will never sit in the same room with each other, or who haven't connected since their high school graduation two decades ago. I just don't want or need to know the mundane details of the day-to-day lives of other people. When I want to know how a friend is doing, I call them instead.
And Facebook keeps changing its privacy settings without telling people. I was mightily pissed off when I found out that my photo album had gone public without my knowledge or consent. I dumped my account, and I'm not going back.
The stupid thing about Facebook and many similar Internet Era businesses is that they're worth so much money mainly because of economic rent accumulating from network effects that lead to natural monopolies.