Did you know for every picture, personal photograph, content, post, action you make you give up your copyrights and facebook can do with it whatever it wants to do? I am sure 95% of facebook users do not know that.
The truth some times can be cruel but facebook has probably more data than your goverment, also more reliable, update to date, and know you things about you and your “friends” even F.B.I. doesn’t. They can create psycological profiles for every single user.
They use our personal data for marketing, companies invest in their statistics they produce on daily basis, that can be political exit-polls, sports, athletes, games, pretty much anything you can think of.
Account deletion: They only allow you to deactivate the service, however in help section there is a deletion, however I doubt people know about it, even that requires few weeks of inactivity. And of course once someone cached your page on google, it may be still be accessible via advanced searches.
On the other hand, let’s face it facebook is useful to stay in touch with people all around the world, mostly on-line friends from on-line games,chat rooms etc.
It’s completely up to you weither you need facebook or you don’t. I’m a programmer, a gamer too, I know what I signed up for when I will no longer need it, I will just delete it.
The best you can do is decide if you really need facebook or just logging in/out when you’re bored. You know your needs.