Facebook man logo peeking around Facebook "f" logo with binoculars

Jason Reed/The Daily Dot

Facebook patented a bunch of sketchy methods for tracking you

The social giant claims it doesn't actively use these methods.


Phillip Tracy


Published Jan 11, 2018   Updated May 22, 2021, 5:06 am CDT

Facebook has faced criticism for experiments it conducted on unknowing users, but it’s the mysterious internal projects that should worry people most.

A year-long study by Gizmodo into the People You May Know (PYMK) friend recommendations section uncovered a patent that would allow Facebook to gain knowledge about users by tracking the dust on their camera. This radical approach would allow the social giant to determine whether photos uploaded by multiple users were taken with the same equipment. For example, if a fleck of dust or scratch was visible in the same spot on images taken by two different users, it could infer that they were taken with the same camera.

With that information, Facebook could add everyone you sent a photo to in your “People You May Know” page. It could do the same thing with the metadata of your photo, or the image information that’s accessible to anyone. In this scenario, Facebook would read the unedited name of an image (IMG_XXX.jpg) and compare it to another image (IMG_XXY.jpg) to see if they were uploaded in the same series of photos.

Facebook denied using these techniques in a statement to Gizmodo.

“We’re also not analyzing images taken by the same camera to make recommendations in People You May Know,” a spokesperson said. “We’ve often sought patents for technology we never implement, and patents should not be taken as an indication of future plans.”

Also concerning are Facebook’s ideas of using location tracking to link users. A patent application filed in 2014 explains that it’s not enough to know if users are at the same location at the same time. So Facebook looked into using accelerometer and gyroscope metrics from phones to determine whether two users were facing each other or walking together. It also suggested tracking where users are when they check in at the same time.

Again, Facebook denied ever implementing these strategies. It claims to prioritize People You May Know suggestions based on mutual friends, essentially linking a web of users together with friends of friends. It further assured that it doesn’t use proxies for location, facial recognition, or who you message on WhatsApp, according to Gizmodo.

It does, however, employ so-called “shadow profiles” to indirectly gather information about you and fill in whatever gaps you haven’t already provided. It does so by collecting information from your friends. If one of your friends has contact information about you in their mobile address book, Facebook will take those details and associate it with your account. The social network will then recommend friends who also have your contact info. This all happens in the background without you knowing about it.

The People You May Know section is more important to Facebook than some might think. The more friends you have, the more likely you are to engage with the platform. The more you use Facebook, the more ad money it gets. One accurate recommendation could lead to an additional friend for two people, which could potentially prevent them from moving to a different service.

If you want to take things into your own hands, you can download Gizmodo’s new tool, which monitors all the friend recommendations Facebook presents you.

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*First Published: Jan 11, 2018, 1:12 pm CST