young people annoy you?

From a newsbrief in the December 12, 2005 issue of Chemical & Engineering News, the journal of the American Chemical Society, there is now a device that is designed to “shoo away” teenagers.
The device, invented by Howard Stapleton, emits a high-frequency pulsing sound that almost everyone under 20 and virtually no one over 30 can hear.
Designed to keep young people from hanging out outside of stores, it broadcasts at 75 decibles, which is within government safety limits.
There’s a story about it online at The Age.