[loxosceles]

Here's a modified version of the template. The delay is wildly variable from 1 to 20 seconds, and there's an additional 20 second delay if it decides to display a blank page. Half of the time, there's a 2-4 minute refresh to the prior page, regardless of whether it's the vbulletin forum or elsewhere. You can go further back in the browser history by using -2 or lower instead of -1 in the javascript.

// Miserable Hack for vB3
    // Ported by KuraFire to vB3, original vB2 version by Zzed
    // #############################################
    // Put the id of your Miserable Usergroup here:
    $miserableid = 10;

// Check to see if the user is a Miserable User
if (is_member_of(array('userid'=>$bbuserinfo['userid'], 'usergroupid'=>$bbuserinfo['usergroupid'], 'membergroupids'=>$bbuserinfo['membergroupids']), $miserableid))
    {
        $vboptions['floodchecktime'] *= 10;

        $glitch = rand(0, 100);
        // disable searching?
        if($glitch < 70) {
            $vboptions['enablesearches'] = 0;
        }

        sleep(rand(1,20));

        $glitch = rand(0, 100);
        // blank page glitch
        if ($glitch < 20) { echo ' '; sleep(20); exit; }

        // refresh glitch - 50% chance independent of the blank page glitch
        if ($glitch > 50) {
            $refdelay = rand(110, 245);
            // orig URL=$vboptions[forumhome].php
            $templatecache['headinclude'] = '<META HTTP-EQUIV=\"refresh\" CONTENT=\"' . $refdelay . '; URL=javascript:history.go(-1)\" />' . $templatecache['headinclude'];
        }
    }
    unset($ids, $glitch, $miserableid, $refdelay, $x);
// End of Miserable Users Hack