Facebook Knows How to Track You Using the Dust on Your Camera Lens


“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 sounds similar to old-school police techniques like blood spatter analysis.