I don't have, and never will have, a Facebook account due to privacy concerns (data mining, etc.), and concerns over use/abuse of users' writing/photos/whatever.
Anyone can use your photos/whatever for whatever they want - the general consensus seems to be that if it's on the internet, it's free to use. ZDNet got called out on a photo lifted from another website in a recent article/blog entry in the comments to that article. The author/blogger's response was 'Oh, is that where that came from?' I don't agree in any way with big media's take on copyright, but at least give credit, or better yet, ask permission, for something you're using.
If you don't want people using your photos, don't post them publicly on the internet. Try this: open a browser window to images.google.com, and drag a photo from another website onto the input field. Look at how many places it shows up! Try it with some of your Facebook photos - you may be surprised!