From Wired.COM: 

Say Hello to the Goodbye Weapon

The crowd is getting ugly. Soldiers roll up in a Hummer. Suddenly, the whole right half of your body is screaming in agony. You feel like you’ve been dipped in molten lava. You almost faint from shock and pain, but instead you stumble backwards — and then start running. To your surprise, everyone else is running too. In a few seconds, the street is completely empty.

You’ve just been hit with a new nonlethal weapon that has been certified for use in Iraq — even though critics argue there may be unforeseen effects.

According to documents obtained for Wired News under federal sunshine laws, the Air Force’s Active Denial System, or ADS, has been certified safe after lengthy tests by military scientists in the lab and in war games.

The ADS shoots a beam of millimeters waves, which are longer in wavelength than x-rays but shorter than microwaves — 94 GHz (= 3 mm wavelength) compared to 2.45 GHz (= 12 cm wavelength) in a standard microwave oven.

(more here)