Damn, I remember another Marauder's Map that was just genius! Long story short, Facebook's Messenger automatically geotagged users by default. People reported

Damn, I remember another Marauder's Map that was just genius! Long story short, Facebook's Messenger automatically geotagged users by default. People reported it to their security program, Facebook said it was intended. Then someone made a browser extension that looked up location of active Messenger friends and showed their location on a map. It got increasingly popular. Facebook decided to switch the location from opt-out to opt-in. Some sources: https://www.theguardian.com/technology/2015/may/28/marauders-map-chrome-app-tracks-facebook-messenger https://www.theguardian.com/technology/2015/may/28/marauders... https://www.quora.com/Can-I-still-download-the-Marauders-Map-Chrome-extension-Does-it-still-work https://www.quora.com/Can-I-still-download-the-Marauders-Map... https://github.com/arank/marauders-map https://github.com/arank/marauders-map