Sorry to here that mate! Ladder clamps have a hole through them so you can use a padlock! if im anywhere dodgy i make sure the padlock is on
However, thats easy for me to say being 99% wfp. It would be a right pain in the arse using my set up for all trad work!
Its gota be bungee chords for local trad hasnt it! for easy on and off with the ladder's!