There are a bunch of different frequency ranges they can use, and it's not trivial to jam lots of frequencies without running into legal issues. If you figured

There are a bunch of different frequency ranges they can use, and it's not trivial to jam lots of frequencies without running into legal issues. If you figured out what frequency range the drone is using you might be able to drown it out but the odds seem high that other equipment might be using that frequency band and it could interfere with emergency operations. Like, hypothetical example - a long range hobbyist drone might be hooked up with a SIM card and the cellular network, so blocking it would require blocking cells like the ones used by emergency responders. Shorter range drones are probably using unlicensed bands, and you might be able to block those - but again emergency responders might be using them for short range communications equipment etc. Long range jamming also runs into power issues due to the inverse square law, I think. You'd need to do it directionally, and at that point I think you'd be better off just shooting the drone down with something like a gas-powered BB rifle or net launcher.