Stirring jealous rage out of our closest computer friends with our relationship/ dinner plate/ children/ vacations/ promotions. That's what we use Facebook for, right?
The internet is kind of like TV: If you don't like what you see and hear, turn it off. As a matter of fact, it's even better than TV, because there are literally millions of other things on it, which you could be enjoying instead of projecting your infantile jealousy upon these folks.
The NSA reads and records everything: public, friends only, friends of friends, no one, only me. When you post online under your State issued personae, you become a public figure, without assumption of privacy.