Imagine an island that is more densely peopled than any neighboring land. It is not large, yet so many people inhabit this island that they’ve stacked themselves up in tall buildings that stretch into the sky. These islanders are fiercely proud of their community, and they are wealthy.

Imagine a machine designed to travel great distances at high speeds. By any standard other than its own history, this machine is wasteful and dangerous. At about twenty times the weight and size of a human, these clumsy machines are a permanent, mortal threat to anyone nearby.

Most inhabitants of the small island, having no great distances to travel in their daily lives, do not keep one of these machines on the island. They have safer, less wasteful, and more comfortable ways to get around, starting with the locomotion of their own bodies. Even so, the public spaces of their island are packed with machines brought in by outsiders, which take control of every major path by threat of violence.

Some of the invasive machines provide important services to the islanders; most do not. Yet they are permitted. Machine operators are even offered temporary land to station their enormous wastes upon for periods of several days. The value of the open land consumed by one machine exceeds the value of the machine itself by several orders of magnitude. Yet this land is exclusively occupied at no cost to the machine’s owner.

There is one final detail to report about the machines: they they are loud at all times, but they come with supplemental noisemakers. At the press of a button, the machine will emit a sound that, though muffled in its interior, will pierce the ears of anyone within several blocks, indoors or out. (When disturbed at rest, these mindless contraptions will squeal indefinitely, of their own accord.)

Though described as a safety device, this incredible noisemaker’s closest observed use to that purpose is a threat: run out of the way, humans, or die. At all other times, it serves as a crude communication device whose message disturbs thousands but is ostentatiously brushed off by the intended recipient. It is the worst invention of all time.

There’s one idea the islanders would be wise to borrow (and scale down) from their surrounding countrymen: seal the borders.