A few months ago I was at the gym taking a class with a guy that I tangentially work with. We knew each other vaguely, and had a couple of mutual friends. After the class met a couple of times, he showed up in my “People You May Know” feed on Facebook, for what I believe was the first time.
I assumed this was the fact we had a couple of mutual friends and our phones with Facebook installed were in the same room together for an hour. Apparently not, according to this Gizmodo article.
But the factors Facebook leverages (or is attempting to leverage) to determine who you may know are fascinating.
It might assume two people knew each other if the images they uploaded looked like they were titled in the same series of photos—IMG_4605739.jpg and IMG_4605742, for example—or if lens scratches or dust were detectable in the same spots on the photos, revealing the photos were taken by the same camera.
This is only the beginning of seemingly innocuous things being used as tracking devices, and it won’t be limited to Facebook.