Pentagon Buys Anti-Drone Systems—But Do They Work? by David Z. Morris @FortuneMagazine May 21, 2016, 4:43 PM EDT E-mail Tweet Facebook Linkedin Share icons The Defense Department and the Department of Homeland Security have committed to buy 100 DroneDefender systems, touted as a solution to the threat of malicious flyers using drones to spy, deliver bombs, or drop drugs into prisons. The DroneDefender, developed by the technology think tank Battelle, looks like a really scary gun—but it isn’t quite what it appears. Instead of shooting anything as pedestrian as a projectile, or even a net, the DroneDefender is really more of a gun-shaped radio. Its signal, which reaches about 400 meters according to Ars Technica, can interrupt either the control frequencies of a drone, or its access to GPS coordinates. Get Data Sheet, Fortune’s technology newsletter. Though a Battelle spokesperson told Defense Tech that drones respond to interference by landing, that’s not uniformly true. Some drones, robbed of GPS or commands, will simply hover until their batteries run out. That’s often between ten and twenty minutes even for small commercial models, which is a long time for a guard to aim a radio beam. Then, of course, there are the drones that lose their inputs and suddenly develop a mind of their own. A Battelle demonstration video from earlier in the concept’s development shows users appearing to guide drones to a landing using the device’s sights: But the video is a simulation, and though Battelle says DroneDefender has been “successfully tested,” the organization makes no explicit claims that it can take active control of a drone. That would be an extremely tall order, given the diversity of drones and control schemes out there. Further, while even high-end drones currently have weak control encryption, the very appearance of tools like the DroneDefender is sure to trigger higher standards. A solution along these lines seems inevitable, and Ars reports that the similar Dronebuster is already in the hands of a Federal government customer. The makers of the Dronebuster, California’s Flex Force, say they’re planning a version that can actually issue commands to a threatening drone. For more on drones, watch our video. But less than a solution to the problem of drones and security, these tools seem more like the first move in what is sure to be a constantly-evolving game of cat and mouse between the makers and users of drones, and those who want to bring them down.