In the skyscraper where my company is HQ'ed the leasing office requires mag locks and oversees the door cards. Our suite is always locked. Occasionally executives come for a visit or someone forgets their card (usually on a Monday). We have a spare for these occasions, although it wouldn't kill us to burn a calorie answering the door.

It is a small company and we all know each other. We can hear someone knocking on the door. So - the cards really aren't the problem. The building-required mag locks are.

2 of the other companies on our floor have "public reception" doors that aren't locked during business hours. Sometimes on sort-of holidays like today (Columbus Day) the leasing office forgets to re-program the maglocks on those public doors - leaving them unlocked until business hours are over. It has happened often enough that the receptionist next door cc's me on her requests to the leasing office to have the door locked on odd days. I set a calendar reminder to go over and tug on their public door. Twice (of about 20 times) I've found it unlocked and sent a reminder to the leasing office.

As ever security is only as good as the humans running it.