The U.S. Army is already using fully armed robots in Iraq, and now it's rolled out the Black Knight Unmanned Combat Vehicle. It's pretty much a giant tank with robotic capabilities, armed with a 30mm gun and a machine gun. Soldiers can steer and control it just like a radio-controlled car, complete with a video viewer that lets them know where to drive and shoot. But the Black Knight is also capable of much smarter, potentially more sinister tricks.
The Black Knight is able to survey an area and plan a route, then drive along that course and avoid obstacles without human intervention. Remember that robotic gun that went berserk and killed nine people in South Africa? Imagine that rolling along at 65km/h.
But relax. According to the beast's maker, BAE Systems, it's not going to shoot unless a human tells it to. "The command to fire would always be made by a remote Soldier and only after the data necessary to make positive identification is received." But isn't that what that South African machine was supposed to do, too?