title: WebSocket SyntaxError: An invalid or illegal string was specified
body: <p>I'm getting a <code>SyntaxError: An invalid or illegal string was specified</code>, while trying to connect to a WebSocket on Firefox.</p>
  
  <pre><code>&lt;!doctype html&gt;
  &lt;html&gt;
    &lt;head&gt;&lt;meta charset="utf-8"&gt;&lt;/head&gt;
    &lt;body&gt;
      &lt;script&gt;
      var socket = new WebSocket('127.0.0.1:1234');
      &lt;/script&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Why do I get this error?</p>