i have an idea forming in my head
Arm-trapping fire-alarm immolates Samaritans: "Cory Doctorow:
In 1938, Modern Mechanix magazine ran an article on a new design for a fire-alarm box. It had an arm-hold trap built in that held the alarm-puller in place until the fire department arrived -- the idea was to lock prank-alarm-pullers in place (of course, if you were dumb enough to pull an alarm during a fire, you were horribly trapped alive in the flames until you succumbed to immolation or asphyxiation).
THE sending of false fire alarms by mischievous persons may be eliminated through use of a newly developed call box. To use the device, the sender of an alarm must pass a hand through a special compartment to reach the signal dial. Once the dial has been turned, the sender’s hand is locked in the compartment until released by a fireman or policeman with a key.
(Via Boing Boing.)