In the UK there is a network of banks that issue cards and sign up retailers. They at least have the influence and muscle to enforce certain standards among the retailers displaying the familiar Visa and Mastercard logos.
But how does a UK bank rein in the sleazy strip joint in Bangkok which makes a habit of adding a couple of noughts to customers' bills?
The Office of Fair Trading and the Consumers' Association are adamant that the card issuers must stand by their logos wherever they are displayed, and take responsibility if a purchase goes wrong.
The banks say the Consumer Credit Act is unclear on the issue, and deals abroad should not count. As far as foreign transactions are concerned, their objections to taking responsibility are not at all unreasonable.
Ambiguity is the worst of all possible worlds and the sooner the OFT completes its review of the Act so that consumers and card issuers alike know the rules, the better.