You could probably use pretty standard ECM techniques to figure out what is a drone and what isn't by listening for their control signals. Of course that wouldn't help with autonomous drones, but those are still a ways off.
A laser sounds pretty good, they're big but you can swivel the beam very fast since you just have to move the mirrors. And they don't fall back to earth like bullets do.
EMPs are hard to produce without explosions of some kind[1], the energy requirements are similar to lasers but the power is way higher. They're hard to make directional, too, leading to a lot of collateral damage whenever you set one off.
"Of course that wouldn't help with autonomous drones, but those are still a ways off."
I can assure you that those are not a long way off. Fully autonomous drones can be deployed today by anyone with a few hundred dollars and a little electronic skills.
A laser sounds pretty good, they're big but you can swivel the beam very fast since you just have to move the mirrors. And they don't fall back to earth like bullets do.
EMPs are hard to produce without explosions of some kind[1], the energy requirements are similar to lasers but the power is way higher. They're hard to make directional, too, leading to a lot of collateral damage whenever you set one off.
[1]http://en.wikipedia.org/wiki/Explosively_pumped_flux_compres...