How Facebook knows you're you (without knowing your name)
If you've watched the news at all lately, you've no doubt heard about the latest internet scandal involving Facebook. But what exactly is going on? What or who is this Cambridge Analytica? What does all this mean for you? In this multi-part series we'll break things down into an easy-to-understand way and give you all of the details about what Facebook gathers and what it does with what it's gathered.
Before we get into Cambridge Analytica and the current scandal however we first need to have a foundational understanding of what Facebook gathers and how they can use it to know who you are without actually having your name attached to anything. The fact of the matter is they use a method that is basically the same as what many large companies in the world use, a method that isn't nearly as anonymous as you may initially be led to believe.
What Facebook gathers
First off, what data does Facebook actually gather about you? Well, to put it simply: everything. Facebook gathers as much data about people as it possibly can. This data is not just limited to things that you post or people you're friends with but is much wider in scope. Facebook collects things like what websites you visit, what products you shop for and what things you search for. If you have the Facebook app installed on your phone it gathers things like who you call, when you called them and how long you talked. The same can be said of text messages as well (who you've texted, when you texted, etc).
Don't have a Facebook account? No big deal, Facebook still tracks your data in much the same way. Many popular websites use Facebook's social media tools which allows them to put things such as "Like" and "Share" buttons on their site. This means, even if you're not logged in, or don't have an account Facebook can still gather at least some data. If it's possible that Facebook can track it, chances are it is indeed being tracked.
How Facebook "anonymizes" your data
So now that we have an idea about what data Facebook gathers about both it's users and non-users what does it do with that data? The first thing they do is "anonymize" it. How do they do this? The most common method is through a process called Hashing. Hashing takes your "Personally Identifiable Information", usually your name and sometimes your address , email or phone number and by using a series of complex algorithms creates a unique and seemingly random sequence of numbers and letters called a Hash. In other words, they turn you into a number. Once this process is completed, all of the additional data that is harvested is tied to your Hash. This allows Facebook and it's partners to identify you without actually knowing your name.
So for example, if your name is Jane Smith and you have an email address of janesmith01@email.com and live at 123 King Lane in Omaha, Nebraska, Facebook takes this information and makes it look like this:
CF3A9077257A67688EBA74130AA7D0B743FEBE81CA9AE7567F39F995895864D0
This is your Hash, it is completely unique so instead of Facebook knowing that Jane Smith called her mother at 10:02am on Sunday it just knows that "User: CF3A9077... called contact "Mother" at 10:02am on Sunday". If an actual person were to look at your Facebook data they wouldn't see your name, just your hash so they wouldn't know your name was Jane Smith but they could still see that you made the phone call.
Who's following who?
So far this doesn't sound too bad right? I mean, it could be worse couldn't it? I mean really, what can Facebook actually do with this information that's tied to your hash? Well, it turns out that Facebook can follow a hash just as closely as they do a person. They can discern likes, dislikes, habits, beliefs, political affiliations, personality, and more. Essentially, they can get to know you better than even your best friends and family members. They can determine where you work, where you live and where you like to hang out. Go to the gym each day at 8am? Take your phone (w/the Facebook app) with you? Search for some sportswear on a shopping site? Facebook can now determine that you're a workout warrior.
In essence, it is effectively like having someone who follows you around and writes down everything you do. Carefully cataloging it and trying to look for patterns in your routine that can say something about you. Why do they do this? Because that information can be extremely valuable to the right people. Even if your life is "boring" there is an extremely high chance that there's a lot more to you than you give yourself credit for.
So who are these "right people" that value this info so much? We'll to find out you'll have to stay tuned because that is coming up in Part 2.