People need to read the fine print No company or website owns you anything. it's up to you to control what you put up online. I think Facebook is actually pretty good about this stuff, they actually changed their policy a few times and are listening to the community and making changes to the security settings.
Facebook is very good for networking at this point. It's very popular here in Canada, in particular in Toronto, so at this point you are almost *required* to have an account if you want to connect with people. It's very common now for people to just tell you to find them on Facebook instead of giving out emails, numbers or websites. I've done it in the past as well when I photographed at some event and people wanted to know where to find me or the photos. Twitter and LinkedIn are becoming like that as well (must have accounts if you want to look "modern").
Personally, I haven't been all that active on Faebook recently. Some of the recent updates have broken things for me (for example, I couldn't put up photos for a long time) and to this day I can't really access it through my default browser (Safari) without some sort of problem. Then there is all the spam. I get constant invites and messages about all the events, groups, pages, etc. Since part of the reason I started using Facebook ws for self promotion, it's part of the game, but it's still damn annoying. Facebook has become over-saturated with promotion that it's losing it's appeal. I'll continue to have a presence on it for work (promoting future projects I'll be involved with), but that's about it.