Simple shitlist popup:
add shitlisted hostmask
del shitlisted hostmask
look at the list of shitlisted hostmasks
delete all shitlisted hostmasks
maybe a good feature: on unload the script deletes itself and the shitlist table from memory and from mircdir.
Very easy to use.
Doesn't allow adding a hostmask to shitlist if there is 10 or more users found matching the mask..

#############################
#   Script    : Shitlist    #
#   Author    : Shitbreak   #
#   Network   : QuakeNet    #
#   Channel   : #Servicebot #
#   Year      : 2008        #
#############################
on *:load:{
  echo 2 -a * You have succesfully loaded shitlist script by shitbreak.
  echo 2 -a * Checking for the shitlist table...
  if (!$hget(shitlist)) { 
    echo 2 -a * Shitlist table does not exist.
    hmake shitlist
    echo 2 -a * Made the table shitlist.
  }
  if ($exists(shitlist.hsh)) { 
    hload shitlist shitlist.hsh
    echo 2 -a * Loaded shitlist table. 
  }
  if (!$exists(shitlist.hsh)) {
    hsave shitlist shitlist.hsh
    echo 2 -a * Shitlist table was not found from $mircdir $+ : It is now saved there.
  }
} 
on *:unload:{
  echo 2 -a * Thank you for using the shitlist snippet.
  if ($hget(shitlist)) { .hfree shitlist }
  if ($exists(shitlist.hsh)) { .remove shitlist.hsh }
  .remove $+(",$script,")
  echo 2 -a * Shitlist is now removed and the script. Shitlist table is already removed from memory.
}
on *:start:{
  echo 2 -a * Checking for the shitlist table...
  if (!$hget(shitlist)) { 
    echo 2 -a * Shitlist table does not exist.
    hmake shitlist
    echo 2 -a * Made the table shitlist.
  }
  if ($exists(shitlist.hsh)) { 
    hload shitlist shitlist.hsh
    echo 2 -a * Loaded shitlist table from $mircdir $+ .
  }
  if (!$exists(shitlist.hsh)) {
    hsave shitlist shitlist.hsh
    echo 2 -a * Shitlist table was not found from $mircdir $+ : It is now saved there.
  }
} 
on *:disconnect:{
  if (!$hget(shitlist)) {
    echo 2 -a * Shitlist table not loaded, we are not saving it.
  }
  if ($hget(shitlist)) {
    hsave shitlist shitlist.hsh
    echo 2 -a * Shitlist table is now saved to $mircdir
  }
}
on *:exit:{
  if ($hget(shitlist)) { hsave shitlist shitlist.hsh } 
}
menu channel {
  ...Shitlist by shitbreak
  ..Add user:{ 
    set %mask $$?="Hostname for the user" 
    if ($hget(shitlist,%mask)) { echo 2 -a * Error adding mask %mask to the shitlist: Mask is already shitlisted. }
    if (!$hget(shitlist,%mask)) { 
      if ($ial(%mask,0) >= 10) { echo 2 -a * Error adding mask %mask to the shitlist: There are too many ( $+ $ial(%mask,0) $+ ) users matching the mask. }
      if ($ial(%mask,0) < 10) {
      set %reason $$?"Reason to be shitlisted?" | hadd shitlist %mask Shitlisted: %reason | echo 2 -a * Added mask %mask to the shitlist. | kickchannels %mask %reason  }
    }
  }
  ..Del user:{
    var %mask $$?"Mask to be removed from shitlist"
    if (!$hget(shitlist,%mask)) { echo 2 -a * Error removing mask %mask from the shitlist: That mask is not shitlisted. }
    if ($hget(shitlist,%mask)) { hdel shitlist %mask | echo 2 -a * Mask %mask was succesfully removed from shitlist. }
  }
  ..Shitlist list:{
    if ($hfind(shitlist,*,0,w) == 0) { echo 2 -a * Error: Shitlist is empty. }
    if ($hfind(shitlist,*,0,w) > 0) {
      var %i = 1
      while (%i <= $hfind(shitlist,*,0,w)) {
        echo -a ID: ( $+ %i $+ ) Mask: $hfind(shitlist,*,%i,w) Reason: $hget(shitlist,$hfind(shitlist,*,%i,w)) 
        inc %i
      }
    }
  }
  ..Delete all shitlist entries:{
    if ($hfind(shitlist,*,0,w) == 0) { echo 2 -a * Error deleting all shitlisted masks: The shitlist is empty. }
    if ($hfind(shitlist,*,0,w) > 0) {
      echo 2 -a $hfind(shitlist,*,0,w) shitlisted entries will be removed.
      var %i = $hfind(shitlist,*,0,w)
      while (%i) {
        if ($hfind(shitlist,*,%i,w)) { var %rm = $hfind(shitlist,*,%i,w) | hdel shitlist $hfind(shitlist,*,%i,w) | echo 2 -a Removed shitlist entry: %rm }
        dec %i
      }
    }
  }
}
alias kickchannels { 
  if ($ial($1,0) == 0) { echo 2 -a * There are no masks mathing $1 on any channels. }
  if ($ial($1,0) > 0) {
    var %i $chan(0)
    while (%i) {
      var %x $nick($chan(%i),0)
      while (%x) {
        if ($1 iswm $address($nick($chan(%i),%x),5)) && ($me isop $chan(%i)) { mode $chan(%i) -o+b $nick($chan(%i),%x) $1 | kick $chan(%i) $nick($chan(%i),%x) Shitlisted: $2- | echo -a * ( $+ $date $+ ) ( $+ $time $+ ) $+ : Kicked shitlisted user ' $+ $nick($chan(%i),%x) $+ ' from $chan(%i) $+ .  }
        dec %x    
      }      
      dec %i
    }
  }
}
on *:join:#:{
  if ($hfind(shitlist,*,0,w) > 0) {
    var %i = $hfind(shitlist,*,0,w)
    while (%i) {
      if ($hfind(shitlist,*,%i,w) iswm $fulladdress) { mode $chan +b $hfind(shitlist,*,%i,w) | kick $chan $nick $hget(shitlist,$hfind(shitlist,*,%i,w)) | echo -a * ( $+ $date $+ ) ( $+ $time $+ ): Shitlisted user ' $+ $nick $+ ' joined $chan $+ . }
      dec %i
    }
  }
}