title: How to block external hyperlinks in an iframed page?
body: <p>I'm making a website that shows another website in an <code>iframe</code> (cross-domain). The problem is that there are external hyperlinks in the site in the iframe, and I want to somehow block or disable them. I want to block ONLY external hyperlinks.</p>
  
  <p>That is, if the iframed page is <code>example.com/info</code>:</p>
  
  <ul>
  <li>Block: <code>&lt;a href="http://other_example.net/pwn"&gt;Bad Link&lt;/a&gt;</code></li>
  <li>Allow: <code>&lt;a href="http://example.com/donate"&gt;Good Link&lt;/a&gt;</code></li>
  </ul>
  
  <p>How can I do this? Greasemonkey and some kind of script? Or something else?</p>