title: How to obtain this Facebook user id for the like button?
body: <p>Referring to <a href="http://developers.facebook.com/docs/opengraph" rel="nofollow">the Open Graph protocol</a>, I must implement this strange tag to my website in order to add a like-button for it.</p>
  
  <pre><code>&lt;meta property="fb:admins" content="USER_ID"/&gt;
  </code></pre>
  
  <p><code>USER_ID</code> is supposed to be replaced by my actual user ID at Facebook. How do I safely obtain the correct user ID?</p>