title: is it okay to "repeatedly" xss-clean data in CodeIgniter?
body: <p>The following are ways to XSS-clean data in Codeigniter:</p>
  
  <ul>
  <li>set <code>global_xss_filtering</code> in config to <code>TRUE</code></li>
  <li>use <code>xss_clean()</code></li>
  <li>use <code>xss_clean</code> as a validation rule</li>
  <li>set the second parameter to <code>TRUE</code> in <code>$this-&gt;input-&gt;post('something', TRUE)</code></li>
  </ul>
  
  <p><strong>Is it okay to use all or more than one of them on one piece of data?</strong></p>
  
  <p>For example, would it be okay if I still used <code>$this-&gt;input-&gt;post('something', TRUE)</code> even if the data has already been cleaned by <code>global_xss_filtering</code> and <code>xss_clean</code> validation rule?</p>