FedEx wants use flying drones. What could go wrong?

Have your heard that FedEx want to use flying drones in the US? Apparently they want to use it to send packages. What next? UPS to use drones to do door to door delivery ? What are they going to do? Drop packages from the sky to each house? Should we have to be worried being bonked by dropping packages soon?
You know, they are going to have driver-less cars soon. But it'll probably start with trucks. So you can imagine a driver-less UPS truck pull up, opens it's hatch and out comes this hovering flying drone with your package. No harm there. There hasn't been any warning whatsoever about robots taking over the world. It's a novel idea. Nobody has thought about it. So it's probably safe.
You know what will happen? The drones will just hover over the to neighbor's house and ask them to sign for your package.  I'm sure they will be willing to do anything to get a flying drone with 4 spinning rotor blades off their doorstep.
Update: Apparently, Amazon is thinking the same.