title: Get Facebook User Id without Permission
body: <p>Possible duplicate , answered 2 years back <a href="https://stackoverflow.com/questions/8730522/is-it-possible-to-get-the-user-id-without-the-authorization">Is it possible to get the User Id without the authorization?</a></p>
  
  <p>Just wanted to see if there is any mean I can fetch user id without showing permission dialog(not even the public permission dialog)</p>
  
  <p>I have tried playing around with app token but in vain, Searched across documentation found no confirmed answers on this</p>