Actually, I don't (want another tool). So, of course it's a case of "I have no need for Faceboook" (though I do think Facebook is evil).
Now I asked a question. Let me reformulate it: how do you define "social networking"? Why do you thing it is hard to reconcile it with privacy paranoia?
I don't think the term "social networking" is amenable to a formal, logical definition. It's mostly a category used to describe sites like Facebook, MySpace, or Loopt (previously Friendster and Orkut) so any site or service resembling those would be social networking. (Please refer here for the type of theory I am applying: http://en.wikipedia.org/wiki/Prototype_theory)
So far the most successful of those sites is Facebook; Facebook is difficult to use if one is paranoid about one's privacy. None of the other partial or past successes were successful due to their exceptional concern for privacy. One does not join a site designed for sharing things with other people in order to hide things from other people.
Now I asked a question. Let me reformulate it: how do you define "social networking"? Why do you thing it is hard to reconcile it with privacy paranoia?