Homeland Security loves non-lethal weapons, like these sound cannons. And now you can build your own for $US250! Does it really work? Not that well, but it’s great for raves…

Those wacky Ladyada hardware hackers (Adafruit Industries) and Phil Torrone from MAKE Magazine, trawled the net and found the patent from the outside consulting firm that built the device for the government.

They discovered it flashes green LEDs at about 10Hz to induce its effects, and modified a Sears flashlight to build their own version called the BEDAZZLER. And true to form, they’ve put the schematics, source code and circuit board layouts online so you can make one yourself. Watch it in action below. Fun! [Ladyada]