
Have you ever taken one of those ridiculous and inane quizzes on Facebook that tell you which color you are ("I'm Orange! Now what do I do?"), which Harry Potter character you are (see above), or which superhero your dog resembles?
Maybe you hate these quizzes and avoid them completely, but do your friends on Facebook take them? If so, all your private info is likely being shared with the quiz developers - whoever they may be. This access to your personal information has alarmed many groups, including the ACLU. Here is a warning from the ACLU of Northern California:
Even if your Facebook profile is “private,” when you take a quiz, an unknown quiz developer could be accessing almost everything in your profile: your religion, sexual orientation, political affiliation, pictures, and groups. Facebook quizzes also have access to most of the info on your friends’ profiles. This means that if your friend takes a quiz, they could be giving away your personal information too.
The ACLU of Northern California has heard from thousands of concerned internet consumers using the popular social networking software, Facebook, about privacy issues. The ACLU went digging and found there is good reason for concern: as it stands, quiz developers have access to just about everything in your profile and postings and those of your Facebook Friends.
Here are a series of screenshots where we show exactly what happens when you take a quiz or run other applications on Facebook:

As you can see, Facebook tells you specifically that it will let the application developer "... pull your profile information, photos, your friends' info, and other content that it requires to work.
This is the privacy problem. Your friends are agreeing to share your information without your knowledge or consent. Not good.

These, I believe, are the default privacy settings for applications. As you can see, you or your friend are agreeing to share a lot of personal information with a completely unknown party.
Even if you are careful about your privacy settings in Facebook, quiz developers probably will be able to access your profile and your postings through the accounts of your Facebook Friends. To drive the point home the ACLU created their own short, instructional Facebook quiz [1]. (And no, according to their privacy policy, the ACLU will not collect or sell your information from their Facebook quiz.) Even though I was expecting some kind of revelation it was a bit creepy to suddenly see my Facebook profile information and photos start scrolling on the screen.
More on this story from the San Jose Mercury News [2].
Links:
[1] http://apps.facebook.com/aclunc_privacy_quiz/?ref=mf
[2] http://www.mercurynews.com/topstories/ci_13210334?nclick_check=1