Briefcase security, then and now:

In 1925, August Eimer invented the case above, which emits smoke when torn from its owner’s hand “in the form of a continually issuing cloud that will envelop the container and serve to unmistakably identify its purloiner, necessitating discard of the container by the thief if he would make his escape.”

In 1989, Isaac Soleimani offered the model below: As the thief is running off, you activate a radio signal that releases a latch, “with the result that the briefcase falls on the ground, leaving the thief only with the handle.”

It seems there’s always an element of slapstick. “The handle could also be spring-loaded so that upon remote triggering it could clamp down hard onto the thief’s hand, clamping the fingers between the handle and the top of the briefcase, thereby inflicting pain to the thief, causing him to drop the briefcase.”