I know its an old topic but I'm getting a script to help with this. I'm in the process of testing it out.
Its been created to suit my hosting as mine has blocked certain ports, but the script should ban most afaik. Also you are able to ban/unban IP's, it will keep a list and a reason for the banning. It records which proxy vote went to which site and also allows banned users to contact you should they need to appeal.
I'll be back with more info
