Locked Inside 5er

[Cbrez]

DW read about folks getting locked inside their 5er by someone closing the grab bar across the door while they were inside. Most seemed to be pranks, although one reported being locked in while robbers cut the chain and stole the portable generator. I am not too worried about this, seems like it's probably pretty isolated, but DW is not so trusting. Trying to think of a way to secure the grab bar so it cannot be easily folded while at the campsite. Has anyone heard of this and have a solution?