I’ll see your drone mounted pistol and raise you a ground based RF cannon to thwart your attack…  Obviously not intended for personal use, and not a “firearm” (I’m secretly pining away for the day when TFB covers lasers and phased plasma rifles as common platforms), but still an interesting evolution in the escalation of technology.

AUDS is designed to disrupt and neutralize Unmanned Aerial Vehicles (UAVs) engaged in Hostile Airborne Surveillance and potentially Malicious Activity.

The AUDS system combines electronic scanning radar target detection & classification, Electro-Optic (EO) tracking and directional RF inhibition capability over three independent RF bands.

The system basically integrates a tracking and identification system with the ability to disrupt the communication system.  I’m not sure if this would actually affect any drones that are preprogrammed, unless it could interfere with the GPS.  I assume it would be trivial to tie this into some sort of anti-aircraft projectile (it would likely be crossing the line for defense of property–though if I start seeing pizza and amazon drones filing my sky…).

You can find more information at their website: http://www.liteye.com/auds.html