title: Facebook scraper cache isn't refreshing
body: <p>Around two weeks ago I added some additional og tags to a page so that more images show up when people share the page on Facebook, like so:</p>
  
  <pre><code>&lt;meta property="og:image" content="http://www.arthackday.net/img/about/Arthackday_About_How-it-works.jpg?zuckerderp=1391735492"/&gt;
  &lt;meta property="og:image" content="http://www.arthackday.net/img/about/Arthackday_About_Partners.jpg?zuckerderp=1391735492"/&gt;
  &lt;meta property="og:image" content="http://www.arthackday.net/img/about/Arthackday_About_What-is.jpg?zuckerderp=1391735492"/&gt;
  &lt;meta property="og:image" content="http://www.arthackday.net/video/berlin_poster.jpg?zuckerderp=1391735492"/&gt;
  &lt;meta property="og:image" content="http://www.arthackday.net/img/ahd_assets/ahd_logo_black_200px.png"/&gt;
  </code></pre>
  
  <p>However, after two weeks the Facebook scraper "See exactly what the scraper sees" at <a href="https://developers.facebook.com/tools/debug/og/object?q=http%3A%2F%2Fwww.arthackday.net%2Fabout" rel="nofollow">https://developers.facebook.com/tools/debug/og/object?q=http%3A%2F%2Fwww.arthackday.net%2Fabout</a> hasn't cleared the cache and shows only one tag from before I added the new ones:</p>
  
  <pre><code>&lt;meta property="og:image" content="http://www.arthackday.net/img/ahd_assets/ahd_logo_black_200px.png"&gt;
  </code></pre>
  
  <p>These are all the things I have tried to force it to refresh. None worked:</p>
  
  <ul>
  <li>Adding URL parameters to the new images with a new value that changes every time the page is loaded.</li>
  <li>Entering the URL at <a href="https://developers.facebook.com/tools/debug/" rel="nofollow">https://developers.facebook.com/tools/debug/</a>.</li>
  <li>Doing the same while logged into Facebook.</li>
  <li>Doing the same while logged in as an administrator of the Facebook page associated with the site.</li>
  <li>Doing the same on a laptop centered in a pentagram drawn with goat blood (and some chicken blood... I ran out) while holding a voodoo doll resembling Mark Zuckerburg.</li>
  </ul>
  
  <p>Any ideas on what I'm missing?</p>