title: Verify Facebook Access Token for specific App
body: <p>I need to verify that users on my iPhone app are actually logged in to my Facebook app.  I'm able to verify their user id by retrieving it with their Access token:</p>
  
  <blockquote>
    <p><a href="https://graph.facebook.com/me?fields=id&amp;access_token=XXXXXXXXXXXXXXX">https://graph.facebook.com/me?fields=id&amp;access_token=XXXXXXXXXXXXXXX</a></p>
  </blockquote>
  
  <p>The security issue I foresee is that, they can send me any valid access token, and it will return their user id.  I need to also validate this token is for my specific app.  Is there a way to return the Application ID in this request to validate that?</p>