Total fuss about nothing if you ask me. It's quite simple (people getting into bizarre legal semantics aside) - if you fly with vulnerable people / under 18s on a frequent basis, go and get CRB checked. It's nothing new - Air Cadet organisation instructors have been doing it for years. It's the way of the world now, resistance to it is futile and a waste of energy quite frankly. If you don't fly with vulnerable people / under 18s on a frequent, carry on as normal. To suggest that all FIs, just because they are an FI, need CRB checking is plain wrong.