>This myth that never ending transactions can happen is ridiculous.
I've used Pay-by-Bonk quite a bit on my debit card, usually in pubs or supermarkets. I've never been asked to enter my PIN, which I had believed I would be every so often. Perhaps it is because I have interspersed my Pay-by-Bonk payments with Chip-and-PIN transactions and withdrawals.
I am cautious with it and insist on taking the receipt. And I usually take some cash-back, so that I only need to use my card once or twice in the evening.
I have heard on Radio 4 that some pubs and nightclubs have decided to stop using Pay-by-Bonk, due to lost or stolen cards being abused to the tune of around £100 over an evening across multiple transactions. This money, in at least one case, was refunded by the issuing bank.