Mine

alias blacklist {
  /write blacklist.txt $address($1,2)
  var %c 1
  while ($chan(%c)) {
    if ($me isop $v1) || ($me ishop $v2) { mode $chan(%c) -Q+b $address($1,2) | kick $chan(%c) $1 12Blacklisted2:4 $iif($2,$2-,no reason)
    }
    inc %c
  }
  msg #seen_my_att 12 I am now blacklisting2:4 $$1 $iif($2,12reason2:4 $2-)
}

alias unblacklist {
  msg #seen_my_att 12 I am now unblacklisting2:4 $1 
  if ($read(blacklist.txt,r,$address($1,2))) { write -d $+ $readn
    var %b 1
    while ($chan(%b)) {
      if ($me isop $v1) || ($me ishop $v2) { mode $chan(%b) -b $address($1,2) }
      inc %b
    }
  }
}

on *:join:#:{
  if ($me isop $chan || $me ishop $chan) && ( $read(blacklist.txt,r,$address($nick,2)) ) {
    ban -k # $nick 2 12 [- 4Blacklisted.12-]
  }
}