I was in Tesco today - the guy in front of me was paying by credit card. The assistant swiped the card and from what she said a message had came up on the screen asking that the card be verified by telephone with the bank. She took the card and went off to the customer service desk to phone the bank (or their agent) The guy seemed slightly embarrassed - another assistant said "Don't worry - this is a random check which happens every so often. The amount of the bill was £3.84 !!!
Are retailers asked to carry out such checks at random? I would have been tempted to say - get lost - can I have my card back. Would Tesco have returned the card?