8 Technologies That We Should Never, Ever Build

7. Nanobot Weaponry

It can be argued that the increasing automation and "techifying" of warfare is saving lives. With robots and drones in the field, you don't need to put as many human lives on the line.

However, with nanotechnology moving further to the fore, do we need to draw a line somewhere?

Swarm technology would essentially be the 21st century equivalent of unleashing a plague of locusts - or a biological weapon - on the enemy. They could be used to block sunlight, destroy resources, jam communications and restrict movement - all without putting a single boot on the ground. Make them self-replicating and there is virtually no defence.

They cannot be shot at or bombed, they cannot be disabled or captured, they act more like an infectious disease than a weapon. What's more, the problem with a swarm is that it doesn't discriminate.