I met someone on holiday who told me they had actually been banned from the entire city of Brighton. How would you enforce this? Is there a list somewhere where you can see who has been barred from where?
If this is an antisocial behaviour order it is enforced by the local police and residents. Frequently taken out on shoplifters, vandals and other dimwits, who the shopkeepers know only too well so there are plenty of folk to dob in the trespassee. I think the lists of local ones are handed round by the fuzz....