The app and its brethren harvest data about non-users through their friends' contact lists. Here's how to extract and eliminate yours. reading time 2 minutes When you sign up for Facebook, Instagram, ...

Facebook has a tool that allows people to delete their personal contact information — even if they never shared it. Any friend who has shared their address book with Facebook to find other friends ...

You can remove followers on Facebook by changing your follower settings. You can also block or add followers to a restricted ...