In a five second search of Das Google...
So, for $3000, you can jam drones up to 1000 meters away.
Thus, not only do you wipe out drones flying, but also have the possibility of wiping out portions of cellular phone service in the same area. Drones work much like cell phones on any one of a set of frequencies in the alloted band.
...and that's why this is a pain in the butt to solve.