Refuse the sale as well as the entry

A ban belongs to the business that imposed it. A resort refusing a skier has said nothing about that person's right to buy a cinema ticket from another company, and no venue can reach outside its own door.

A named customer is somebody you know. An IP address is a mobile network with a town behind it, and a household shares one router. So a strong match refuses at the door and a weak one quietly raises it with a supervisor — and an address can be blocked for a period but never indefinitely, because the people it would catch for ever would never learn why.

A refusal reads "see a supervisor" and nothing more. What somebody is accused of is a private matter about a named person, and a scanner held up in a queue is the worst possible place to publish it — often the person on the door should not know either.

A ban with nothing written down cannot be reviewed, appealed or explained six months later when nobody remembers the night. Lifting one keeps the record, because "we banned him and took it back" is a better history than no history.