The Active Denial System, called ADS for short, is a non-lethal weapon that has been in development for 15 years. It delivers a man-sized heat beam on a radio frequency of 95 gigahertz. Accessing the same millimeter wave technology used in airport body scanners, the beam penetrates only 1/64th of an inch into a person's skin and cornea, heating water molecules in the tissue and generating an instinctive urge to run from the effect. The prototypes the military demonstrated where installed on two different vehicles -- one built onto a heavy expanded-mobility tactical truck, the other onto a Humvee. "You're...