So keep your valuables close. ESPECIALLY WHERE YOUR POWER ARMOR SUITS ARE CONCERNED. Had the one my PC was wearing and a 2nd reserve at the Rocket stored in Tony Stark style. Fast traveled on business somewhere for a game day. When I returned, my 2nd PA was gone....
So NPCs WILL "permanently borrow" your items if you leave them out in the open. Store anything of value in a container that belongs to you or locked away in a safe. That should stop the 5 fingered freebie discounts that are going on in your hood