title: Vimeo - thumbnails for private videos
body: <p>I need to get a thumbnail image of a Vimeo video with following privacy settings:</p>
  
  <ul>
  <li>only people with private link can watch</li>
  <li>video can be embedded only on specific domains </li>
  </ul>
  
  <p>I tried oembed:</p>
  
  <pre><code>function grab_vimeo_thumbnail($vimeo_url){
      if( !$vimeo_url ) return false;
      $data = json_decode( file_get_contents( 'http://vimeo.com/api/oembed.json?url=' . $vimeo_url ) );
      if( !$data ) return false;
      return $data-&gt;thumbnail_url;}
  </code></pre>
  
  <p>But it only works if privacy is set to "Anyone can watch". There is not "thumbnail_url" argument available when I set required privacy restrictions as I need.</p>
  
  <p>Some ideas how to do it? Thanks</p>