I have found that
Code:
on *:join:#: {
  if ($nick == [8_) {
    mode $chan -v $nick
    mode $chan +m
    .notice $nick Please ID to receive a voice!
    msg $chan $nick has be devoiced due to suspicious activity!!!
    msg $chan $nick has be devoiced due to suspicious activity!!!
    msg $chan $nick is not the real user unless he/she is ID and Chanserved for a VOICE!
    ifelse { halt }
  }
}

Works but only if the person is called "[8_" lol, how do I make it work if "[8_" is any part of a persons nick?