This could have been a deleted scene from Children of Men.
US security forces turned the piercing sound on their own citizens yesterday to widespread outrage. Pittsburgh officials told the New York Times that it was the first time "sound cannon" had been used publicly.G20 protesters blasted by sonic cannon
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects