If you like/fear drones, you’ll love/dread this.

DARPA has been fantasizing mechanical humming birds for over two decades, and now Aerovironment is selling them. But, they’re expensive and inefficient. The quadrotor, by contrast, is simply a very dangerous toy that can be stamped out by the hundreds of thousands and can do everything a drone can do, i.e., carry video cameras and explosives, but in miniature, e.g., flying through windows. Think of the quadrotor as a flying landmine. ’nuff said.