title: How to know if a user logged in through facebook
body: <p>I have both DNN 6.2 and DNN 7.0 running on my localhost.</p>
  
  <p>I have successfully set up facebook authentication and got facebook login working.</p>
  
  <p>Now, through the code how do I know if a user is logged in through facebook and how do I get his facebook ID, his friends info etc.,</p>