It's not all bad....really
I couldn't let this pass without commenting - in Ireland we already have this - if you work with children you have to get Garda (Police) clearance. If you want to go with the kids on a scouting weekend, or local football team same procedure.
You do it once, get your form filled in - sent off and if it comes back you can give a copy to which ever club or association or whatever, want to work in a school, got the form ok then etc
If it doesn't come back then no scouts trip for you. End of.
Yes the UK government seem even more adept at loosing the keys to the database doors than the Irish government, but have it no you don't need to have it if you are a parent for your own kids, but you do for other peoples!
It's not perfect - I don't think that you can have a perfect system, but it does mean that if you work with kids that someone somewhere has checked you before signing the form to say off you go.