clipped from: blog.wired.com 
The Pentagon wants to be able to peer inside your apartment building -- picking out where all the major rooms, stairways, and dens of evil-doers are.
The U.S. military is getting better and better at spotting its enemies, when they're roaming around the streets. But once those foes duck into houses, they become a whole lot harder to spot. That's why Darpa, the Defense Department's way-out research arm, is looking to develop a suite of tools for "external sensing deep inside buildings." The ultimate goal of this Harnessing Infrastructure for Building Reconnaissance (HIBR) project: "reverse the adversaries' advantage of urban familiarity and sanctuary and provide U.S. Forces with complete above- and below-ground awareness."