This information about Facebook's changing terms of service--which is applicable to everyone on Facebook, even if you agreed to prior terms of service--is a bit disturbing. Here's the deal: anything you publish on Facebook belongs to Facebook. Not to you. To them. For a more logical and clear run-down on it, I refer you here and here.
So, if I were to post my book on Facebook, then it would belong to Facebook, not to me. No, that's not fair. And no, it's not likely that Facebook would do anything about it (i.e. try to publish my book/steal my idea/sue me for publishing my own book). But it's a stupid policy of Facebook's, and one that I'm not going to play around with.
I'm not saying go out and pick up the pitchforks and torches over this one. But I think Swivet has the best advice with this:
So am I going to delete my Facebook account? Nope. Facebook is still a valuable networking and promotional tool. ... But of you're a writer/photographer/creator of any kind, I would suggest not posting any intellectual property on Facebook that you may want the right to sell later. Just in case.If you've got any intellectual property on Facebook, you might want to consider taking it down. If that policy existed for Blogger, I'd delete my hook from the sidebar over to the left, and I'd hunt down posts about my book and delete them. It's one thing to let the world see your work--it's another thing to be at legal odds about the ownership of your work.