This is my first modification to be posted. However i did not create it as it is actually a part of vbulletin. a friend of mine pointed it out to me. So i posted the idea. Thanks WM.
This modification will redirect Banned Users to [Only registered and activated users can see links. ]. Banned users will not be able to access your forum and create new user id's. Only after a bann is lifted and they clear their cookies then they will get access again.

This modification is endorsed by theybannedme.com website, they put a link on their front page to this post...

Confirmed working on vB 4.0.0 if you use a replacement variable - <head>
Thanks for the contribution icarusforde

Instructions:

Admin CP->Styles and Templates->Style Manager->Your Skin Style->Edit Templates->header->Paste this at the very top..........

Code:
PHP Code:
<if condition="$bbuserinfo['usergroupid'] == 8">
<meta HTTP-EQUIV="REFRESH" content="0; url=http://www.theybannedme.com">
</if> 

If your banned usergroup id is something other than 8, change the value to what yours is........

Also, you can change the url to anything you want, in case you ever want to change it............

Updated>>> slightly changed version, thanks to DungBeetle= This will redirect a particular user

Code:
PHP Code:
<if condition="$bbuserinfo['userid'] == X">
<meta HTTP-EQUIV="REFRESH" content="0; url=http://www.theybannedme.com">
</if> 
This modification can also be used for a wide variety of creative purposes.

Tested on VB 3.6.x, 3.7.x, and 3.8.x

Confirmed working on vB 4.0.0 if you use a replacement variable - <head>

Please click INSTALLED if you use this