The Department of Homeland Security announced that it will start using unmanned drones to patrol the southern border of the United States, similar to the ones the military uses against Taliban insurgents in Pakistan. The Federal Aviation Association has approved the measure which would allow drones to fly along the Texas-Mexico border and throughout the Gulf Coast. "These types of flights aren't useful everywhere, but in some places they are part of the right mix of infrastructure, manpower and technology to improve border security," said Homeland Security Secretary Janet Napolitano in a speech at the Center for Strategic and International studies.

Employing lethal military technology that the U.S. uses against its enemies in a domestic context begs many questions, least of all being, is there a danger in using them? For the answer, we turn to a man who knows a bit about danger. Noah Schactman is a contributing editor to Wired magazine, and edits its national security blog, Danger Room. Schactman says the chances of a commercial or private aircraft colliding with a drone are "infinitesimal."