A Security Magazine blog makes the appropriate point that “Not every incident of unauthorized access is a criminal break-in – some of the most common types spring from common courtesy, like holding the door for a colleague.”
Holding a door open? Yes, it’s called tailgating and occurs “when one or more people follow an authorized user through a door, reducing the number of people who badge in, (thus) reducing security’s insight into who is inside the building when, and exposing the building to risk.
Other examples are cited involving propping doors open, lost, stolen or loaned keys, access cards and levering doors – “Doors can be opened by screwdrivers, crowbars or many other tools.”
Simply, doors aren’t to be messed with, whether in the interest of courtesy, carpentry or anything else that weakens their primary function of regulating authorized access to a facility that needs to remain secure.