Lens Scratches and Gyroscopes: “People You May Know” on Facebook

Facebook Panopticon
CC image by Flickr user Joelle L

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.

Reply All Podcast Takes a Look at Facebook Advertising Algorithms

Magnifying Glass

The continuously excellent Reply All podcast starts with the question of if Facebook uses your phone mic as a source of advertising information and digs through the way Facebook advertising aggregates and processes data. They at least scratch the surface enough to know it will be hard to gauge how deep it goes.

If you aren’t listening, there are too many good episodes to list here. Just start with the recent two-parter, a gonzo investigation Indian computer tech support scams. Part One. Part Two.