and at worst is actually counterproductive?
A CRB check does not mean that you are 'safe' to work with children, it just means you haven't been caught doing anything wrong.
I worry that people will start to trust the CRB check rather than their own instincts ... 'x makes the hair stand up on the back of my neck, but they must be ok because they've been checked ...'
The thing with the adventure playground beggared belief in my opinion, the idea that children are safer with some 'play ranger' who's been checked than with their 'unchecked' parent is ludicrous.
After all, nursery staff are all CRB checked, but that didn't stop the vile goings on at the Little Teds nursery.