The Pentagon's "less-lethal" microwave-based crowd-control weapon – the Active Denial System (ADS) – produces potentially harmful hotspots when used in built-up areas, and its effects can be intensified by sweaty skin, tests have revealed. The flaws call into question the weapon's usefulness in hot conditions, like those in Iraq. The ADS fires a microwave beam intended to heat skin without causing damage, while inflicting enough pain to force the victim to move away. However, tests of the weapon showed that reflections off buildings, water or even the ground can produce peak energy densities twice as high as the main beam....