I wrote previously about Facebook hacking, which is something everyone needs to be aware of, but there is a more immediate Facebook danger which millions of people every day are already exploited by. Not only could it lead to insecurity, but your personal data is being exposed to advertisers every time you take one of those “What kind of hamburger are you” quizzes.
Facebook applications get access to all data of users who sign up, though users sign up for dozens of one-time use applications like these quizzes without thinking twice. There are hundreds of applications springing up every day, and Facebook’s model of implementing no technical sandboxing and policing applications when things go wrong is completely unscalable.
That quote, from LightBlueTouchPaper.org, summarizes the research they have done on how your personal data is being shared by applications on Facebook. Essentially, any time you approve an application (a quiz, a game, etc) to access your profile, you have allowed to access everything in your profile. These applications are created by third parties, and as proven by the article above, they don’t necessarily follow Facebook’s terms of service all the time.
The (rhetorical) question is, why would anyone ever need to access your personal data in order to allow you to take a quiz? They shouldn’t.
So what can you do? Quit taking all those quizzes, first of all. Quit using other apps as much as possible. This includes Zombie Wars or whatever the latest thing is. Use Facebook to connect and talk to people with the tools Facebook gives you, which is what it was made for.
Sophos provides an excellent walkthrough of setting your privacy options in Facebook, and general tips on staying safe.