There are several other angles yet to be shown which are more disturbing.
First we need to seperate little drones from the big UAV military ones. The greater worry is the weaponisation of the small cheap commercial drones which is what is being discussed here I think. If someone has got The General Atomics MQ-9 Reaper then we have a bigger issue.
Swarming drones or using a large group of them at the same time is a new tactic that has been discussed. Sending 50+ at a time with small explosive charges to overwhelm the defences ability to deal with so many of them. Even the close-in computerised defence weapons would find this a problem.
You do not need to communicate with the drone when it is off and running. You can simply program in a dozen GPS based way points and let it go. With batteries improving all the time this gives you a 30 minute one way run at a target. It also makes it a fire-and-forget weapon so the owner can eject it and run away.
There have already a number of attacks in this form,
https://en.wikipedia.org/wiki/Caracas_drone_attack
