title: Twitter API returns error 215, Bad Authentication Data
body: <p>I am trying to call following Twitter's API to get a list of followers for a user.</p>
  
  <p><a href="http://api.twitter.com/1.1/followers/ids.json?cursor=-1&amp;screen_name=username">http://api.twitter.com/1.1/followers/ids.json?cursor=-1&amp;screen_name=username</a></p>
  
  <p>And I am getting this error message in response.</p>
  
  <pre><code>{
      code = 215;
      message = "Bad Authentication data";
  }
  </code></pre>
  
  <p>I can't seem to find the documentation related to this error code. Anyone has any idea about this error?</p>