This reminds me of an article a while back: `Facebook can track who you know using the dust on your camera`[0] [0] https://www.dailymail.co.uk/sciencetech/arti

This reminds me of an article a while back: `Facebook can track who you know using the dust on your camera`[0] [0] https://www.dailymail.co.uk/sciencetech/article-5262297/Facebook-track-using-dust-camera-lens.html https://www.dailymail.co.uk/sciencetech/article-5262297/Face...