It's like anything else... Use it sensibly.. and FB is fun. I've never been "trapped" by anything there.. I don't post drama... Jokes, cat pics, interesting videos... and that's about it...
I love Facebook and joined in 2007 or 08 when we lived in Uganda. It was and is brilliant for keeping up with family and friends. I don't post a lot on politics - either US or UK, but I will post things in favour of gay marriage or congratulating another state for passing a gay marriage law. One friend who unfriended me was opposed to gay marriage, in fact I think she was opposed to gays in general.
QS, do you post a lot of cat photos?! I have a couple of friends who are always posting photos of their cats or their hamsters. Ack!!!!!!!!!!!!!