I’d noticed this the other week in the local supermarket. There was a notice saying that payment by credit card would only be accepted upon presentation of valid ID. This is not a great problem for most Italians who never leave home without the ‘Carta d’Identitia’, but for anyone who is not from the Bel Paese, it could be. Today I bought a new pair of shoes and was asked for ID because I wanted to pay by credit card, and being good ID card carrier, this was no problem for me.
Stop reading, start speaking
Stop translating in your head and start speaking Italian for real with the only audio course that prompt you to speak.
However, if you happen to find yourself in Milan for whatever reason and you want to splash out a bit, and pay with plastic, make sure you have some form of ID with you. A passport would be ideal, or otherwise a driving licence with a photo on it should be OK. Knowing this may save you some slight embarrassment, I hope.
Apparently the banks here have recently advised anywhere that accepts credit cards to request ID, presumably to curb rising incidences of credit card fraud. I would imagine that this has become a requirement throughout Italy too.