Checking doors are secure used to be an obligatory part of night duty foot patrol until the early 80s (by which time it usually, but not always, was restricted to shop and business premises). It was so much part of the routine, and so fucking tedious, it was referred to as spending the night shaking hands with door handles.
You lot that are whinging deserve to have your fucking stuff nicked ... and deserve to be absolutely fucked off it you try and report it afterwards or claim off the insurance.
Can't be bothered taking care of your stuff? Fine. Just don't expect anyone else to be bothered when it goes missing.
If you don't want the police on patrol to look after your stuff when it is left unattended why not just put a big notice in the window?