Missing Privacy: Tracking Your Friends' Habits With Facebook

How You Can Use Facebook to Track Your Friends’ Sleeping Habits (+Video)

Søren Louv-Jansen | February 21, 2016

Like most of my friends, I use Facebook on a daily level. I use the website, the Facebook app, and the Messenger app. It should come as no surprise, that Facebook keeps track of every time you visit them through any of those means. The creepy thing is, that your friends can keep track of this too.
You might have heard about this recently. On Friday (19th Feb) I was surprised to find this post at the top of Hacker News. I’ve been toying with this idea for a while, and open-sourced the entire codebase last year. I clearly wasn’t the only to have this idea. Here’s how it works.
Last year Facebook launched messenger.com — a web-based version of their Messenger app.

New Facebook 'Nearby Friends' Can Track Your GPS Location Continuously. Source: http://thehackernews.com/2014/04/facebook-nearby-friends-track-Gps-location.html

<more at https://medium.com/@sqrendk/how-you-can-use-facebook-to-track-your-friends-sleeping-habits-505ace7fffb6#.gbzwwuk44; related links: https://defaultnamehere.tumblr.com/post/139351766005/graphing-when-your-facebook-friends-are-awake (Graphing when your Facebook friends are awake. February 15, 2016) and http://www.ibtimes.com/how-track-your-facebook-friends-new-app-makes-it-eerily-simple-1940629 (How To Track Your Facebook Friends: New App Makes It Eerily Simple. May 27, 2015)>