Active Denial System

The Active Denial System is a non-lethal energy weapon system currently under development by the U.S. military.
Development
It works by directing electromagnetic radiation at a frequency of 95 GHz toward the subjects. This frequency means the radiation is in the microwave region of the electromagnetic spectrum. In comparison, a standard microwave oven cooks food with about 2.4 GHz waves, so the ADS's radiation is more energetic, but much less prone to penetrate skin - the military says the effect "penetrates the skin to a depth of less than 1/64 of an inch." The focused beam is supposed to be effective at a range of up to 700 yards.
The energy in the waves turns to heat upon skin contact and immediately heats water molecules in the skin to around 130 degrees Farenheit, causing an intensely painful burning sensation. A spokesman for the Air Force Research Laboratory described his experience as a test subject for the system: "For the first millisecond, it just felt like the skin was warming up. Then it got warmer and warmer and you felt like it was on fire.... As soon as you're away from that beam your skin returns to normal and there is no pain."
Military researchers claim the system causes no long-term damage and the Department of Defense hopes to use it to avoid killing rioters or insurgents. The leader of the Joint Non-Lethal Weapons Directorate currently adminstering the program says the system falls somewhere "between bullets and a bullhorn" - designed to force people to back down without the complications of killing them and bystanders. Proponents of the system hope to arm troops "with a nonlethal capability in military operations other than war" - citing, for instance, peacekeeping and crowd control operations.
The system is scheduled to be deployed for evaluation from late 2004 until the end of 2005.
Controversy
While the effects of this range of radiation have been studied by the military for years, and the official position is that it is safe, but the studies have not been released publically. Despite testing on volunteers, the possibility of damage to tissues other than skin, such as eyes, is still present.
The military flatly says the Active Denial System "is absolutely not designed or intended or built" for torture and have extensively checked that the system is within the bounds of U.S. and international law. Nonetheless, activist groups protest that the ADS would be a very effective torture device, citing the Abu Ghraib prison scandal as an instance of illegal but apparently unchecked abuse. The Center for Torture Victims argues that the technology and lack of control would make abuse likely, intended or not.