Disable Mouse On Lock In Ubuntu

I like to have my monitors off to save power when the screen is locked. Unfortunately it seems like my mouse is rather sensitive so nearby movements cause the screens to come back on. I preferred to have only a keyboard press do this.

#!/bin/sh
XINPUT_ID=8
gdbus monitor -e -d com.canonical.Unity -o /com/canonical/Unity/Session |
  while read x; do
    case "$x" in
      *.Locked*) xinput --disable $XINPUT_ID;;
      *.Unlocked*) xinput --enable $XINPUT_ID;;  
    esac
  done

This script achives that. I have it listed in the startup applications so starts on logon. Use xinput list to find the correct xinput ID.