>I have a friend who has a store that was robbed repeatedly. He installed a vestibule like an airlock with two doors. On the wall were pictures of previous thieves, and a very obvious camera system. All customers coming in were remotely vetted. Cause trouble in the store, and your picture goes on the Wall Of Shame.

This is why stores in the ghetto have such systems for dealing with customers. It's not because their owners and employees like dealing with people through a tiny bank teller-like hole. It's from painful experience.

(Same goes for why certain items are locked up, only retrievable by an employee, in drugstore chains' outlets in certain locations but not elsewhere.)