There is a
good free RBL that checks users against a database of known forum spammers. You can check a users IP against it before allowing them to do anything on your site. Here is some example
PHP code:
Code:
function blacklisted($ip)
{
$dnsbl_check=array("dnsbl.tornevall.org");
if($ip){
$rip=implode('.',array_reverse(explode(".",$ip)));
foreach($dnsbl_check as $val){
if(checkdnsrr($rip.'.'.$val.'.','A'))
return $rip.'.'.$val;
}
}
return false;
}
Basically just pass the IP to this function and if it comes back as true, then the IP is listed.
Enjoy!