Someone

on *:join:#lowmotion:{
  set %whoisnick $nick
  set %whoischan $chan
  whois $nick
}
raw 319:*:{ 
if (!%whoischan) { halt }
  var %n = 1
  while ($read(channelban.txt,%n)) {
    if ($+(*,$read(channelban.txt,%n),*) iswm $3-) msg %whoischan !tb %whoisnick 1 You are on a banned channel, Leave them and come back!
    inc %n
  }
  unset %whoisnick
  unset %whoischan
} 

___________________________________________________________________________________________________

Banned channels

#pcmaster
#pcw95
#100pc
#pest_control
#pc-ownage
#pcw
#zips
#pest-control
#pestcontrol
#rips
#pest-hq
#luckypc
#p-control
#axe
#pc
#pest-time
#pest-owner
#pc100
#thepc
#pest
#rspc
#pcultimate
#goodpc
#pestmasters
#pcproduct
#nonoobspest
#osiris
#88
#mpk
#r-p
#lure4life
#blasphemy_public
#lures_n_more
#hq
#arpc
#apc