Whenever a user wants to use the Facebook credentials to log into a third party apps like Foursquare or Candy Crush, the user had to give the app access to all data that FB has on you. Till now there is no way to escape this loophole. Last year Facebook made an announcement that it would be implementing a new API which allows the user to decide what sorts of private information to share with such app . The implementation is no longer an announcement, it has come to action. Now when you log In Using Facebook you’ll be redirected to a landing page where you can select which data you want to share with the app.