Harvard student Aran Khanna, a Harvard University student, discovered ‘A Marauder’s Map’ that could sense and give the geolocations of your friends on the messenger. Khanna had received an opportunity to work as an intern for Facebook but destiny had planned something else for him, as after publicly stating the risk associated with the app; Facebook withdrew his candidature as a summer intern. Facebook told him that “the extension violated the Facebook user agreement by “scraping” the site”.
Source: https://thehackernews.com/2015/08/facebook-fired-intern.html