I never did like youth curfews, ever since Jack Straw first mooted the idea back in 1996 - for more details, see my No Curfews website. The arguments against the Redruth curfew (BBC News: Redruth curfew two weeks on) are no less valid; what is of questionable validity is the Police's claim that this curfew is "voluntary" and the result of "bottom up" policing.
It is true that the capitalist Establishment can sometimes exercise control over people without coercion being used; for example, people who pander to the Establishment's divide-and-rule tactics by being racist, sexist, homophobic, disablist and - last but not least - ageist, are rarely forced into such behaviour or rewarded for their actions. But, since such prejudice is the result of sustained brainwashing by the Establishment over a long period, it is highly debatable whether such behaviour can be called "voluntary".
Besides, the Redruth curfew is hardly non-coercive. As the BBC News report states, the Police "can issue social orders against parents or children who flout the curfew" - which makes it about as "voluntary" as a request by your boss :-(
As for "bottom up" policing - did the Police's "consensus" include the views of the local young people, whose liberties are being swept away by the curfew? Indeed, a number of adults, notably a local representative of the Childrens Rights Alliance, has blasted the curfew as unfair. And how much were the local population consulted on whether money could be spent on youth facilities rather than illegal wars, Trident missiles, tax breaks for the rich, etc?
Indeed, this "voluntary" curfew should not only be seen as an attack on the civil rights of young people. It should also be seen as a warning of the implications of other "voluntary" measures, such as "voluntary" opt-outs from maximum working hours (which, even if there is no enforcement of longer working hours by employers, can result in the erosion of real wages as employers can expect workers to make up the shortfall from a living wage by working overtime).
On the other hand, I am all for "bottom up" rather than "top down". Not only the legal system, but also government and the economy should be run from the bottom up, by workers committees. This will necessitate a revolution, followed by the government, bosses and the capitalist Establishment being forced into a "voluntary" surrender of their power to workers!