I am currently, in what I call "Facebook Re-hab" for over a year now. I think I have kicked the habit. But wait...I have replaced it with the Delcamp Site, which I find much more interesting.
I have never used Facebook, Twitter or any other social network site. I think these sites are dangerous and ultimately too invasive for everyone who participates in them. If you have ever been involved in any kind of litigation and gone through weeks of depositions and discovery you would have an idea of how easy it is for even a half-baked team of low IQ lawyers to pull enough innocent information off anyone's Facebook site and present it in a way that makes them look like the paradigm of the Anti-Christ.