They did this in an area in bristol a couple of years ago. I think the curfew was around 9pm. It did catch out a fair few parents out at the pub while their youngsters were running round the streets.
I think that maybe at 17 it would be embarrrasing to be sent home; up to 14 or 15 would be better. Anything that makes uncaring or un-bothered parents more responsible for their badly behaved offspring is a good idea in the making.
ummmm yes they do, and worse - it was an area I was working in at the time and it wouldn't be unusual for even younger kids, 8 or 9, to be out at that time, whilst minding their younger brothers and sisters!
Mixed feelings. For younger kids definitely a good idea (although as has already been said, they shouldn't really be out!). I used to go out at 17 and i was very responsible so I'd have been really p'eed off at being sent home at stupid o clock.