In 2014, Facebook filed a patent application for a technique that employs smartphone data to figure out if two people might know each other. Kashmir Hill and Surya Mattu of Gizmodo write about some of the things Facebook knows, and deduces, about us.

Here is the link – https://gizmodo.com/facebook-knows-how-to-track-you-using-the-dust-on-your-1821030620