From what height would these drones drop their packages? If it was from six feet or more, that would harm any fragile contents. But if they gently place them on the ground, their rotors have the potential to hurt humans. How would they guard against that? And how much would an injured person be able to sue Amazon for? It's not as if Amazon doesn't have deep enough pockets to attract the attention of a lawyer or two.
There have already been several cases of people injured by drones.
This Australian triathlete was injured when photographer's drone crashed next to her mid-race.
Singer Enrique Iglesias' hand was injured by a drone during a concert in Tijuana.
A number of people were received minor injuries from a low-flying drone at the Virginia Motorsports Park during the Great Bull Run (a local version of Pamplona).
So far none of the injuries have been serious. But take a look at this drone race and ask yourself if these objects couldn't cause serious injuries. They sound like huge mosquitoes, and look like malevolent flying spiders. But with those spinning rotors, they're really just flying knives.
As anybody who's ever had a model airplane can attest, control of a remote flying object is often far from perfect. Here's a compilation of crashes, if any proof of that is needed.
What happens the first time a drone get sucked into a jet engine and causes an airplane crash? A near miss occurred just eight weeks ago above New York City. Passengers are unlikely to take kindly to the idea of their plane dropping out of the sky because some photographer wanted an aerial shot.
And what about terrorists? How convenient would it be for them to deliver a small bomb to, say, Times Square on a Sunday afternoon? Or to a football stadium? Or to an outdoor concert? This wouldn't even require their presence. (And wouldn't the terrorists see this as poetic justice, given the number of deaths we have inflicted upon them via drone?)
These things will probably wreak all sorts of havoc in the near future.
Update: This article on the threat from drones just appeared on 7/25 in the Post.