I am employed in the non-aligned military industry, read non-NATO, and we take an active interest in many fields of military endeavor including drones and robotics.
Presently both American and Israeli UAVs use non-ISM/WiFi radio channels. along with encryuption, and the Achilles' heal remains communications. Only the larger devices are able to carry navigation systems independent of GPS.
The Aaronia device is also dependent upon the mobile object emitting signals. Many drones are not interactive, or passive, saving their payload for use upon their return to their base.
Our research included participation in events organised by entities such as the Fighting Robots Association, technically observing police activities involving robots, etc.
Presently the US military uses broadband RF jamming but this technology is easily circumvented using multi-mode signalling such as optical communications.
The American War in VietNam proved that high-tech can be beaten, further demonstrated by the fact the current US battle tank, Abrams tank, can be taken out by an oil drum with a concave end as winessed on November 27, 2004, December 25, 2005 and June 4, 2006, etc.
Still, the military seemingly will buy almost anything ubtil they find it is less than satisfactory.
Assuming we're dealing with quadcopters here, (Predators being a different proposition altogether), I would expect they're going to be astonishingly noisy in RF. 4 cheap electric motors and a bunch of Mhz electronics are going to be shouting all over the spectrum, aren't they? Then there are any control signals and telemetry going either way