I've found it easiest to deal with persistent problem makers, spam bots etc by creating a new usergroup and adding those nuisances to that usergroup. I've then added the following code to the headinclude of each style.
<if condition="$bbuserinfo['usergroupid'] == XX">
<meta HTTP-EQUIV="REFRESH" content="0; url=http://www.myenemy.com">
</if>
Change XX to the usergroup number you've just created.
['usergroupid'] == XX">
Change the following address to wherever you want these people/bots redirected to.
http://www.myenemy.com
Add them to the new usergroup, delete their posts and enjoy a laugh too.