Geofencing is a great (better) solution.
This is purely a radar that can detect drones, where larger radar possibly doesn't pick them up (too low, too small, etc).
It's good that it also picks up people and vehicle movement at an airport for example, safety wise, but it's a whole other thing to be monitored, needing a person to be ready to act, then they can't disable a drone, so a further section to deal with the problem. Somehow.
DJI really are leading the way with no enabling flight in the first place, a much better solution, but it will only stop the average hobbyist (at the moment also only flying DJI drones), as noted many times any determined nefarious users would hack a DJI drone, or just fly other brands / self built drones.
Wouldn't it be nice to know just how many flights are for nefarious purposes, over the number of flights by regular hobbyists / commercial use ?
Or, how many criminal pilots vs hobbyists / commercial users ?
What, maybe 0.01% would be doing (wanting to do) something criminal ?
I don't think GOVCOs (or industry that would have a use for this kind of tech) would have a clue on this either . . . what companies making these anti drone guns, radar, etc depend on, making something out of nothing (or close to it).