The Verge: Facebook now lets you block background location tracking on Android

"Facebook is adding a new privacy control to its Android app today that allows users to prevent the social network from accessing their location when the app isn’t open. The update comes just days after CNBC reported that Facebook’s security team had used location information to track missing interns and users deemed to be threats."

https://www.theverge.com/2019/2/20/18233424/facebook-android-location-data-privacy-controls