There is a field next to the Microsoft building I used to work in, and for a time, people parked their cars out on the field, presumably because finding a proper parking space in the garage became difficult due to overcrowding. To prevent people from parking in the field, Security placed a large log across the access to the field. The technique worked: Nobody parked in the field any more.
Some months later, our building had a fire drill, and everybody dutifully filed out of the building and waited until the all-clear signal was given to return. Normally, people would wait in the field, because that is the designated assembly area for the building, but oh wait, Security blocked off access to the field. Instead, people waited in the fire lane.
Good thing this was just a drill, because they would have gotten run over by a fire truck.
I pointed out to the Life Safety Security representative who was running the fire drill that Parking Security had created a life safety hazard. My observations were duly noted, and it looks like somebody actually paid attention, because a few weeks later, the log was removed. Now if there's a real fire, we can actually reach our designated assembly area.
I just found it ironic that the Security department created a safety hazard.