Does anyone remember a short cartoon about a "portable hole"?
Some boy-inventor comes up with a portable hole -- essentially black pancake-like objects that you can place on any surface and have an instant hole. You can also remove the hole just as easily.
After the boy demos the portable hole with much fanfare, one night a crook steals his bag of holes (using a cane to pull it). We then see the crook placing a portable hole outside of a bank vault to effortlessly rob it. I think this news comes to the inventor (who is busily making more holes, in a manner akin to making flapjacks on a griddle). But eventually, the crook places one of the portable holes on the outside of another building, and crawls inside. A police officer then happily removes the hole, trapping the crook inside. This building turns out to be none other than the State Prison. Perhaps this toon helped demonstrate that even the most amazing innovations can be used either for good or for evil.
The concept of a portable hole appeared in at least one Looney Tunes short. Wile E. Coyote dug a hole in the road to trap the Road Runner. But the Road Runner promptly "picked up" the hole with his beak and took it to a high (suspension?) bridge, and placed the hole there. Sure enough, the coyote fell through it.
Portable holes were also potential inventory in some role-playing games.