My address and phone number are unlisted,† and I don't have a Facebook account. While these measures don't prevent people from finding me if they really want to, it does reduce uninvited contact. It also makes it a little harder to figure out who my friends are. On Facebook, I gather, you have total control over which "friend requests" you accept, and it's easy enough (technically, if not socially) to "unfriend" someone whose behavior displeases you. That kind of relationship (which I may be misrepresenting since, as I said, I don't use Facebook) seems to lack the subtleties of real-life friendships—"school friends," "work friends," "workout friends," "friend friends," etc.—but my inner geek appreciates the clean lines between "friend" and "not-friend" relationships.
I wish real-life relationships came with that kind of clarity. Am I still friends with someone who meant the world to me twenty or thirty years ago, but who never initiates contact or acknowledges phone messages, emails, or cards? There's been no falling-out, no disagreement...just a gradual drifting apart. I'd hardly know where to start if we ran into each other today, but I'd feel obligated to try, just as I feel obligated to keep sending birthday and holiday cards. It seems like a minor investment of time and money, and who knows, maybe someday it'll pay off. In the meantime, I think I already know how it feels to have a Facebook "friend request" ignored.
† A "privilege" for which I pay a monthly fee, oddly enough. You'd think it'd cost nothing to have the phone company leave me out of their directory (which they no longer even print, I think; isn't it just online now?), since I'm sparing them the effort of verifying and including my contact information. But no, I have to pay to not be listed. I assume it has something to do with lost advertising revenue, but that's a post for another day.