Basically just allows you to stop people from certain chans joining your chan. If someone who is in #badchan or #badchan2 joins your channel, this script will ban them.

Usage:

-Edit #yourchan and #badchan to your channel name and the chan you want banned.
-Put the code in Remotes (alt+R)

Note:

You can have as many banned chans as you want, just edit the if statement, eg:

if (#badchan isin $3-) || (#badchan2 isin $3-) || (#badchan4 isin $3-) || (#badchan4 isin $3-) {

or just one chan would be: if (#badchan isin $3-) {

on *:join:#:{
if ($chan == #yourchan) whois $nick
}

raw 319:*:{
  if (#badchan isin $3-) || (#badchan2 isin $3-) {
    msg #yourchan $2 is in a banned channel.
    ban #yourchan $2
  }
}