title: Why is a <style> block considered unsafe markup?
body: <p>I recently plugged in <a href="http://code.google.com/p/pagedown/wiki/PageDown" rel="nofollow">PageDown</a> to santize some HTML input coming from a textarea, and I noticed that it trims out "style" elements.  </p>
  
  <p>I was just wondering why these are considered unsafe ?</p>