How Facebook Tracks You

Facebook is used by over a billion people around the world according to the company.  It contains people's most intimate secrets and has more personal information about more people than any other site in history.  It is a literal treasure trove (ie- money machine) for advertisers targeting certain segments of the population.  However, it is also used by people trying to find you for reasons other than friendship or advertising.  The only way to be truly private on Facebook is to not use it at all.

But if you insist on using it, there are some things you can do.  Before we get to that, let's talk a little bit about how Facebook works.  Facebook itself, or anyone who has access to your Facebook can determine a number of things about you just by your friend list.  Your friend list makes it almost impossible to maintain anonymity.  So if you think you are outsmarting everybody by not putting your hometown or your high school on your 'About Me' page, you are mistaken.

Here is an example of what is known as a social graph:

Thank you to mark-photo.com for allowing me to share this graph with my readers.

Facebook has one of these for all 1.1 billion of their users (in fact, there are apps out there, like Touchgraph, that will let you create one of your very own).  I know it looks sort of complicated, but it is very simple.  Each dot on the graph represents a person that the Facebook user knows.  Lines between two dots represent mutual friends.  Clusters of friends were labeled by the user.  The central figure in the middle is actually the Facebook user's spouse who are commonly centerpieces on these graphs as spouses often know many of the same people.  So this Facebook user is friends with a number of people from his old high school, many of whom are also friends with each other.  The three lines heading off to college represent someone from his high school that went to his college.  The line from high school to family represents someone from his family who went to his high school.  The elementary school cluster suggests that he moved to a different area or changed school systems (such as private or charter to public or vice-versa) at some point because not a single person from his elementary school knows anyone from his high school.  The six dots to the right of the high school cluster (that sort of look like a stingray) appear to be some sort of group or club from back before he was married because none of them know his wife or went to any of his schools.

So even if this Facebook user chooses not to share where he went to high school, the information is still quite obvious and is available to anyone who goes through and looks at the high school cluster profiles as undoubtedly, one or more of his friends have indicated where they went to high school on their profiles. This would reveal where he grew up.  The elementary school cluster would show where he used to live before he moved.  The same applies to his choice of college.

This is a lot of information gleaned from someone I don't even know and I don't have any access to their account.  And I'm not even an expert at this sort of thing.  Imagine the possibilities for an expert with the proper access credentials, which are quite easy to obtain by hackers or others wanting to know more about you.

Each one of us has a unique social fingerprint, and Facebook does an excellent job of bringing this information all together.  It is quite difficult to hide your fingerprint.  Perhaps you already know that Facebook collects too much information and you've tried to take measures to maintain some semblance of privacy in this part of the online world.  For example, maybe you have created a fake name on Facebook to maintain your anonymity.  This may help a tiny bit to keep casual users from identifying you, but like real life, changing your name won't change your social fingerprint and even casual users would be able to easily identify you by the people you have friended (for example Mom and Dad, brothers and sisters, aunts and uncles are all readily apparent on Facebook even if you haven't tagged them as relatives).

Perhaps you've thought REALLY hard about this and decided to friend a bunch of random people to confuse things.  Maybe you have had added many, many friends so those with access to your Facebook would have a harder time determining your personal information like where you went to high school.  But since all of your random friend requests probably do not know each other, you will still be left with the clusters seen above, along with single unconnected dots of the people you added in a futile attempt to gain some anonymity.  Here is the chart above after adding 48 random people who do not know each other or any of your other friends:

See the 48 individual dots at the bottom left?  Those are the 48 people you added to 'muddy the waters.'  As you can see, it didn't change your social fingerprint very much.  Also, Facebook monitors accounts for people friending people they don't know (ostensibly to stop spammers) and will slow your ability to make friend requests, turn off that ability for a period of time, or close your account (especially if the account is not seasoned/new).  They know that you don't know any of those 48 people and so do you, now that you know how to read a social graph.  Changing your name and adding random friends does nothing to change your social fingerprint.

The NSA's phone metadata collection program works much the same way as described above.  This is why they collect metadata information and don't really care about the content of your messages or phone calls (though they listen to calls, including calls of world leaders, and read messages regularly for no apparent reason).  They feed this information into supercomputers put it all together to build electronic dossiers on all of us.  The more datapoints they have on each of us (such as IP addresses, emails, credit card data, banking, travel, etc), the higher the quality dossier they have.  They can gather far more intelligence this way than actually listening in on your phone calls or reading your emails.

Stay tuned for Part 2 where I will discuss strategies for increasing your privacy on Facebook.