The Paranoid's Guide to Facebook

Over half a billion people use Facebook around the world. It is the single largest phenomenon of human connection in history, not to mention the biggest thing ever to hit the Web, and a source of enjoyment for millions. But it's becoming more and more of a love-hate relationship. We love using Facebook and other online social networks, but we hate the ever-increasing privacy and security concerns.
Those concerns about privacy on Facebook have caught the attention of the U.S. Government: Congress recently sent Facebook an open letter asking the company to explain the disclosure of user identities to third parties (as originally reported by the Wall Street Journal), and how the company plans to address this issue. James Clarke, senior consumer technology analyst at Mintel International, makes very clear what's at stake: "It's in Facebook's own interests to provide a safe environment for users to enjoy; the value of their business depends on it."
The wheels of Government will inexorably turn, albeit slowly, and you need to secure your privacy now. Here are some steps you can take to keep your private information private on Facebook.
Facebook Places
Using Facebook Places has its benefits, but whether you're using a mobile device or a desktop, telling the world where you are has major disadvantages. When you broadcast your location, you're exposing vulnerabilities for an ill-intentioned person to swoop up. And your iPhone or Android-based smartphone can broadcast your exact geographic coordinates down to a few feet.
If you use Facebook Places, remember that Facebook instantly defaults your privacy setting so that "Everyone" can see your profile. And that doesn't mean everyone on Facebook, but everyone on the Internet.
Surf over to the Account tab in the upper right corner and select Privacy Settings. From here, you can set who can and can't see your profile, and how much you want others to see when you upload comments and images. If you don't like the idea of anyone knowing where you are, you should disable Facebook Places completely.
Disable Facebook Places: To do so, log into Facebook, and select Privacy Settings from the Account drop-down menu (upper-right corner of the page). From there, click Customize settings--the link is at the bottom left of the page. The last line under the Things I share section deals with Facebook Places. Click Edit and select Disable.
This stops Places from operating on your profile, but it does nothing for what your friends do.
To stop friends from broadcasting your location, scroll to the Things others share section. At the bottom of that table is the Places section. There, click Edit and select Disable.