I like Facebook...I havent had a problem with it yet. But everyone be careful, dont click on the ads on the side, because they might redirect you to a harmful site. My friend once got a virus on his from doing that...so just dont click on them, especially the ones that say "make 100 bucks an hour." My guess is that those are scams. So if you decide to continue to use facebook, make sure you are careful what apps to put on.
The site is trustworthy enough, and it is a lot of fun to use. The ease of navigation is more complex than it used to be. Also more visual aids have been added (use of Flash/Java), which could cause privacy concerns. Also, some 3rd-party applications have been flagged for exploits and worms.