Friday, August 22, 2008

Thoughts on Facebook and Privacy (or Lack Thereof)

After watching a DEFCON 16 presentation about the vulnerabilities in social networks, I reflected further upon Facebook and the privacy it offers you and me, which is close to nil. Your guarantees to privacy on Facebook depend on a multitude of assumptions, all of which are quite poor. [B]

First, you are trusting that the Facebook developers have implemented the privacy controls correctly such that there is no inadvertent information leakage on the site as a result of bugs. I write code for a living, and let me tell you, bug-free code does not exist. Facebook, like other applications, has had its share of bugs to scramble to fix in the past (including at least one truly amateur mistake) and the future will be (and the present is) no different.

Second, you are assuming that you can configure the myriad privacy options correctly such that every piece of information on your site is accessible to only those that you want it to be. Are you really sure that marking one person as only being allowed to see your limited profile and specifying that picture as globally viewable, for example, will turn out the restrictions you desire for the correct people? How can you tell which preferences override which? It would certainly be tedious to register other accounts (or use friends') and test various combinations of privacy features against their profiles and I am not aware of anyone that does this.

Third, anyone that can see your information is capable of leaking it to the public. [A] With the addition of every friend you are increasing the chance that your pictures, contact info, videos, etc. will be posted and shared outside of the Facebook walled garden. It is simply not possible that each of your 500 friends is not susceptible to give away information that you thought was just between you and them, especially when they have some kind of (monetary or otherwise) incentive to do so. The scenarios of a rival political party digging up dirt on a candidate and gossip magazines researching what someone did last night both come to mind.

Fourth, all of your information can be accessed by any Facebook engineer or executive who choses to do so. The engineers likely need access to real-world pages to debug their code, and the managers can order information from a compliant underling (if Facebook doesn't have internal tools set up already for them to access this information). And let's not forget everyone else that works there (sales, PR, HR, etc.) who can request your personal information as a favor from an engineer friend.

Fifth, just as with any other website, information on Facebook can be subpoenaed in a trial. Facebook, needing to comply with the law, will gladly turn over your personal information to any judge who so wishes.

Sixth, let's not forget the countless ways Facebook could involuntarily compromise your information. A malicious hacker could slurp down personal data off the site. A Facebook employee could negligently leave an unencrypted disk drive with your information on it in a public place. Etc.

The only conclusion is this sound advice: don't put anything on Facebook that you don't want to be exposed to the world. Because chances are, sooner or later, it will be.


[A] This is, of course, assuming that your group of Facebook friends can not be considered 'the public.' With the amount of friends some have, and especially one's willingness to accept any request that comes their way and fire out friend requests at random, this distinction begins to blur.

[B] I was going to add this post to my Facebook Sucks article but it became too long and I thought it deserved a post of its own.


Here is a post for those that want a HOWTO for micromanaging their privacy settings on Facebook. (Even Schneier likes it).

Here is a Slashdot story about a court demanding Facebook information pursuant to a case

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