The idea
The law states that convictions are "spent" after a period of time. However when a CRB check is done, every misdemeanor is reported even if it occured 20-30 years previously. Unless the conviction is for either physical or sexual abuse, there should be absolutely no need for an employer to know about such matters.
Why is it important?
My daughter, now in her 40s, was an extremely wild teenager and got into an awful lot of trouble 20-25 years ago. She is throughly ashamed of that period, but each time she has applied for a job requiring a CRB check, this history is available for employers and potential employers to see.
She works in the care industry and is highly qualified in her particular field of caring for the elderly. She has been turned down on several occasions after excellent interviews and on one occasion was dismissed from her post when a belated CRB report eventually appeared. Fortunately she now works for an employer who had the sense to disregard her teenage rebellion and genuinely saw them as spent convictions.
The care industry is going to need many thousands of carers as our population ages. This draconian check could stop many from gaining such employment.