Or why deleting your Facebook account might be a good idea.

Portrait of Tammy Strobel

Or why deleting your Facebook account might be a good idea.

My Reading Room

Have you ever had a friend suggestion on Facebook and wondered how exactly Facebook knew to suggest them? You’re not alone, Facebook’s ‘People You May Know’ section is one of the most controversial features of the social media website and as it turns out, what you see now is just the surface of what Facebook is capable of.

In 2014, Facebook filed a patent application for a technique that employs smartphone sensor data to figure out if two people might know each other. The details of the patent describe a system that compares the accelerometer and gyroscope readings of phones that are geographically located in close proximity to each other to determine scenarios such as their owners facing each other, or walking together for an extended period of time. If Facebook detected that you probably spent a long time in someone else’s company, it could suggest the two of you as friends.

According to Facebook, the technology in this patent isn’t currently being used. In fact, Facebook has been quick to deny a lot of things it apparently could be using to suggest friends to you: it doesn’t spy on your Wi-Fi network or IP addresses, it doesn’t use face recognition, it doesn’t suggest people that search for your profile, and it doesn’t read your messages or contacts in third party apps like Whatsapp and Telegram (however, it does look at your phone’s default contact list). But if Facebook denies using any of these methods, why does it keep filing patents for even creepier ways to identify potential friend matches?

Another patent filed in 2015 describes a technique that would connect two people through the camera metadata associated with the photos they upload. So for example, if you upload a picture to Facebook, and it has similar metadata to another user’s photo – the patent describes lens scratches or dust on the camera lens being identifiable in the same spots in each photo – Facebook will know the photos were taken by the same camera, and assume both people know each other. According to Facebook, this patent is also not in use, but the fact that Facebook keeps thinking up these techniques is worrying.

Alongside the patents it has for tapping into your phone sensors and camera metadata, Facebook also has patents that explicitly advocate the use of shady practices. One of these is a 2015 patent for “determining household membership” i.e. figuring out who your family members are. According to the patent, the method describes a match value system that determines if someone you may know is a friend, spouse or parent, based on keywords and attributes. However, in the small print of the patent, it also states that household membership can be confirmed via “external feeds, third-party databases, etc.”, which means Facebook isn’t above simply buying your information from a third party data broker.

Facebook’s official stance on these patents is that, while it has sought patents for certain technology and techniques, it has no plans to implement them, and patents should “not be taken as an indication of future plans.” One patent we know Facebook definitely is using is “associating received contact information with user profiles stored by a social networking system.” In layman terms, Facebook is collecting any information it can find about you from other users (“received contact information”) and creating a compiled profile of all of your data. So even if your own Facebook page is sparse on personal details, if someone you’re friends with has detailed contact information on you in their contacts list, Facebook knows about it. These information profiles Facebook creates can’t be opted out of, seen, edited or deleted by you. If Facebook detects that someone else has a contact entry that matches the hidden profile it has on you, Facebook may suggest them as someone you know. It’s one of the most effective ways Facebook makes friend suggestions, because the more friends you have, the more information it can collect on you, which in turn leads to more friend suggestions.

Since being founded in 2004, Facebook has filed thousands of patents. You should be able to feel safe when it says it has no plans to use many of these, but the incredibly invasive nature of many of its patents make that a hard task. And when the number of friend connections Facebook can suggest to its users starts to plateau, what’s stopping it from activating any of those patents?

My Reading Room

One patent we know Facebook definitely is using is “associating received contact information with user profiles stored by a social networking system.”