Does Facebook Own Me?

While I'm not much for technical jargon or political economy, I thought Cowhey and Aronson did bring up a good question at the end of Chapter 5. "Who owns the Information?" In this world where so many people have personal information on Myspace or Facebook who does that information belong to? Does it belong to the individual? Does it belong to the site owners because the person freely gave them the information? Or is it somewhere in between? Do we forfeit our ownership of that information by making it public (I would say no, but I'm sure many others would say yes).
I recall a few months back an uproar over a proposed change to Facebook regulations which would allow them to use personal information, including people's uploaded photos in basically any manner they wanted. Facebook backed down on the changes after the users angrily protested. I was not pleased with what Facebook wanted to do, but did we all have a right to object? Anything we put on Facebook's site we willing shared with them and many other people. Once we've done that who does that information belong to and who can use it? If one of my friends, or even someone posts a picture, I can copy it and keep it for myself as well, is that legitimate? Do I now have some sort of ownership to that photo?
Personally I would like to think that like Intellectual Property Rights personal information about myself remains under my "ownership" even if I have put it on Facebook. If I freely give my credit card number to purchase something online, that site doesn't own that information and can't sell it (although I suppose if I posted it publicly I'm not sure what type of recourse I would have if someone used it). However I have heard of issues with this already in cases of people not being allowed to see their own credit reports or medical records, for whatever reason. What can we do to keep our personal information under our control in an age when more and more personal data is being displayed for the world? Would we have to stop using things like Facebook or MySpace to safeguard our information from being commodified or is there another way?