The US Army's Active Denial System, a "non-lethal, directed-energy, counter-personnel weapon" has finally seen service in Afghanistan.
The ADS works by projecting a focused beam of 3.2mm wave electromagnetic radiation at a human target. This heats the water and fat molecules on the skin, causing their temperature to rise by up to 50C.
The Greeks, of course, thought of it first.
There were safety concerns about the ray weapon in 2007, and these still seem to be a burning issue. The weapon has also been almost immediately withdrawn from Afghanistan without being fired. It seems it has limited uses.
Other problems come from the limitations of the device itself. Rain, snow and fog hamper its effectiveness, and it can be blocked by highly reflective materials such as aluminium foil. In many situations – particularly in busy crowds – working out the right range will be complicated, and there is also the possibility of targets finding themselves unable to move out of the path of the beam.
EoR imagines the Taliban are arming themselves with tinfoil hats. The ADS costs $5 million. A tinfoil hat a few cents (though it might make them more noticeable to passing drones).
Strangely, rubber bullets also appear less effective than they did. The Guardian in 2007 states:
The beam has a range of up to 1km, 10 times that of other non-lethal weapons such as plastic bullets or beanbag-firing guns.
The Telegraph in 2010:
the ADS has a range of up to 500m, 10 times greater than current non-lethal weapons such as rubber bullets.