Facebook is like a dentist. The benefit is that you get to spy on old friends who aren't really friends anymore, but you have to remember that a) the dentist is going to cause you pain, and b) he's going to invoice for for the pleasure of doing so. The difference is that the dentist has your best interests at heart, whilst Facebook has its own best interests as its primary focus, its customers secondary, and hint hint - you aren't the customer.