Or foul the frequency with noise and watch the thing make a soft failsafe landing.
I'm guessing they probably operate on a SINGCGARS radio, which frequency hops 111 times x second. I would think if one were to be brought down, it will be done by a hacker. Given the operational altitude of these things, there's probably very little the average citizen can do, although if it's known where they're taking off and landing from, something along these lines may hae some promise, albeit a quite expensive one...
“Or foul the frequency with noise “
Not possible. Look up ‘frequency hopping”. Their communications can hop frequencies every pulse and the frequency range is extremely wide. The signal is also in the grass already so don’t even hope to overpower it, it doesn’t operate on that level of power. The system also detects jamming signals and keeps its frequency hopping out of that range. A VERY powerful transmitter capable of extremely wideband transmissions can jam that type of signal but only ship and ground based systems have ever been successful at it. They can pulse in excess of 100 megawatts over 100 MHz at a time for a duration of over 10ms. Even then the jamming isn’t always successful. No space or airborne platform has yet to accomplish such a feat. Airborne platforms have jammed only in very short ranges such as 3-5 miles, past that and the pwoer simply falls off too quickly.