Imagine if you will a terrorist cell getting their hands on a drone, or a number of them, and some explosives. No, this is not an episode of 24. The military calls drones unmanned aerial systems (UAS), and they are worried about them. While planes and helicopters are large enough to recognize easily on radar, drones, being smaller, can be mistaken for birds.

That’s why the Pentagon’s R&D wing has been tapped to create a system to protect soldiers on the battlefield and civilians at home, from this ever-growing threat. The Defense Advanced Research Projects Agency (DARPA), the people who brought you the internet and many other startling innovations, have an idea on how to stop “UAS-enabled terrorist threats.” What DARPA is doing is requesting proposals for something they are calling an “aerial dragnet.”

Read More: Big Think