No, it's not the latest ranting of Grampa McSame, but a news item my local San Francisco news affiliate carried. The context was a new way to combat the problem of loitering in high crime areas. The answer is a technology that struck me: "The Mosquito." an ultrasonic device that emits a high-pitched noise that only teenagers can hear.

Marketed under the banner "Kids Be Gone," the device emits a high-frequency modulated tone that has been likened to fingernails on a blackboard or a mosquito buzzing in the ear. Because the ability to hear higher frequencies fades with age, the Mosquito affects only people younger than about age 25. Also, according to the makers and various media reports, the sound does not annoy young children or dogs, only people in the 13 to 25 age bracket.[..]

A website focused on the Mosquito — www.kidsbegone.com — says studies have shown the device is safe and does not damage teenagers' hearing. The effective range is about 50 feet, according to the website.

In a sneaky twist, the same technology is available as a cellphone ring tone, alerting teens to calls that teachers, parents and other adults can't hear. The Kids Be Gone website has a link to the high frequency ring tone. In a test at The Courant, a 22-year-old said he could clearly hear the tone, while several staffers over age 25 heard nothing.

The technology rests with little tiny hair perceptors in our ears that usually die off by the age of 25. Although the manufacturers say that no permanent damage is done from The Mosquito, I'm a little wary of such assurances. The technology has been used in the UK and is now the subject of a protest for its indiscriminate use. (YouTube)