I was running beside the Thames this week when I was whacked by a Mosquito.
Never heard of them?
The Mosquito is an aptly named British-designed security device that emits a high-frequency sound audible only to young people.
If you're under 25, or if like me you apparently boast late-deteriorating ears, a constant whine at 17.4Khz will have you fleeing pretty quickly for some place quieter.
I was in London for a couple of days when the Mosquito struck.
The only way I can describe the noise is as intolerably high pitched. It hit me in an instant and was gone 10 seconds later — you could only hear it in front of one particular house.
Pause between the house and the Thames to admire the view along the river and you'd feel like a dog being tormented with one of those special high-pitched whistles.
Yes, Mosquitos are pretty contentious.
Shop owners love them because they deter "unruly teenagers" from loitering outside, but various legal challenges across Europe have tackled their use.
Critics claim they breach United Nations' and European Union standards for human rights. Someone rather dramatically claimed that using the Mosquito is tantamount to torturing kids.
In my case, it just seemed a bit miserable. No shops were nearby, it was a public path and the Mosquito spoiled the river's ambience. I didn't see the owners of the house and perhaps they've had problems with kids in the past, but it's hard not to picture a grouchy, resentful, bitter old codger.
And use of the Mosquito is quite different from those schemes playing classical music to deter kids from loitering in public plazas and skate parks after dark.
Imagine walking a baby right through a Mosquito's whine. You mightn't even realise why your babe was so upset. Kids at least are smart and savvy and have apparently turned the Mosquito's technology on its head.
As Europe considers their legality, you can now buy a Mosquito-pitched ringtone, meaning teachers and adults won't hear your cellphone if it happens to ring in class.
• Jack Tame is on Newstalk ZB Saturdays, 9am-midday.