title: How does this <video> tag prevent its contents from being downloaded?
body: <p>Taking <a href="https://www.dailymotion.com/video/x60y8sn" rel="nofollow noreferrer">this video</a> as an example, here is the html tag which seems to be the critical piece of content:</p>
  
  <pre><code>&lt;video
      id="dmp_Video"
      style="display: block; width: 350px; height: 197.436px; top: 0px; left: 0px;"
      playsinline="" webkit-playsinline="" x-webkit-airplay="allow"
      operadetachedviewtitle="All Watched Over by Machines of Loving Grace - Episode 3: The Monkey in the Machine and the Machine in the Monkey — Dailymotion"
      src="blob:https://www.dailymotion.com/30c69843-cd99-4101-a8bb-0a6db568dd00"
      controlslist="nodownload"&gt;
  &lt;/video&gt;
  </code></pre>
  
  <p>It is clearly not intended to be downloadable because there is <code>controlslist="nodownload"</code> and I notice that it's quite resilient to casual tampering. I would like to know how this is implemented.</p>
  
  <p>If I delete the surrounding clutter nodes in Firefox, I am able to right-click on the  element but the menu option to download is greyed-out. If I disable Javascript, I am not able to right-click on this element at all.</p>
  
  <p>If I put the <code>https://www.dailymotion.com/30c69843-cd99-4101-a8bb-0a6db568dd00</code> blob url into the browser directly, or use <code>wget</code>, I get a 404.</p>
  
  <p>How have they achieved this?</p>
  
  <p>(I'm not asking you to hack the page for me, I'm asking what I would have to do to make my own videos similarly protected.)</p>