I use facebook quite a lot - primarily it's a great way to run our team with most of the lads being regular users, but also because I worked abroad a lot in my youth and lost touch with dozens of people, most of whom I've now rediscovered thanks to facebook.
I'm not an avid 'status' updater - mine are generally related to the rugby team, some banter over sports events or occasionally major events in my life. And even then I generally don't bother.
As Enicomb says though, it's populated by gullible, frankly stupid people. The security settings are fairly simple (once you've found them!), and you even have to give permission to any 'apps' you might choose to partake in - which is what makes some of these people particularly stupid.