“These devices are indiscriminate and target all children and young people, including babies, regardless of whether they are behaving or misbehaving,” Sir Al told the BBC. “The use of measures such as these are simply demonising children and young people, creating a dangerous and widening divide between the young and the old.”

[Simon Morris, commercial director of Compound Security Systems, which created and markets the Mosquito:] "Police forces will support me with this. Kids will come from various parts of a neighbourhood and congregate in that one spot, like the centre of a wheel," he said.

"What police find is that rather than one group of 20 or 20 kids in one location they will split into smaller groups and the smaller groups cause less problems. Of course it doesn't solve the long-term problem, but it does what it says on the box. It disperses the large groups."

See also: Kids turn "teen repellent" sound into teacher-proof ringtone

This unique toy/teaching aid provides ample amounts of healthy fun along with education and awareness of the security measures that people face in real life. A fun and educational booklet is also available upon request along with other online resources at OperationCheckpoint.com. Additional projects and education on airport and public spaces security is also available at OperationCheckppoint.com.

Our first park was completed over a year ago. It has been a great success, lots of kids have been learning to skate, all of them are improving, and loving it more than ever. We now want to spread skateboarding to a new community in the country, to share it with more kids.

We are looking for donations to help us buy land and materials to make this happen. If you like what we have done with our first park, please support us in building a new one. As with our first park we are relying solely on private donations, so any amount will help!

And the treehouse sites are hardly ever cleaned up. In fact, the children's parents often have only a vague notion of where the treehouse is. They may help to build it, but they don't feel responsible for it. It's out in the woods where only children and mushroom pickers see it: out of sight and out of mind. The mess there would never be tolerated in the back yard, just as most Westerners of today feel really uncomfortable in the stench and litter of Third World villages.

So the next time you come upon an abandoned treehouse site, you might give some thought to the fact that you're standing in the ruins of someone's childhood. The children who used the site no longer exist: they're grownups now, living somewhere else, disposing more rationally of their belongings. And some of them very probably have kids of their own now who are wheedling them to buy a few boards and a box of long nails, a rope ladder and some tarred roofing cardboard. And daddy -- can I please have your old drum kit / dough mixer / rollerskates? I'll take them out of your sight.