No C-UAS system can legally shoot down a drone over US soil without federal authorization

Federal law (18 U.S.C. 32) classifies drones as aircraft, making shooting down even a hostile drone a federal crime with narrow exceptions only for DoD, DOE, DHS, and DOJ under the 2018 Preventing Emerging Threats Act, which expired and has been only partially reauthorized. A local police department that spots a drone over a packed NFL stadium cannot legally jam, shoot, or intercept it. This persists because the FAA treats national airspace as a unified system where any unauthorized kinetic action could endanger manned aircraft, and Congress has not reconciled the conflict between airspace safety and ground security. Every stadium, prison, and critical infrastructure site in the US is effectively undefended.