I use a spring jawed carabiner on the handle lock. I'm more concerned about the lock handle vibrating open, hitting a bump and having the hitch jaws open than having some nitwit purposely pull the handle. And I thought I was overly paranoid about accidental releases!
I do try to remember to do a walk-around when returning to the rig after parking to do a visual check.
'06 2500 Silverado 4X4, Duramax LBZ Diesel, Firestone air bags
'08 Tracker Pro Guide V-16 Boat
'12 Pinnacle 31RLTS