It was almost two years ago to the day when Amazon released a cheeky video detailing its plans to conquer the skies with a fleet of package-delivering drones. We're still waiting for these unmanned aircraft to replace standard trucks and delivery personnel, but it's clear Amazon hasn't abandoned the idea. Earlier this week, Amazon was granted a patent for technology that could enable its future drones, in the event of an emergency, to self-destruct in order to protect people on the ground.