I was just about to edit and add above; all my credit cards are signed with “See ID” on the back. Every single time a clerk flips it over and then asks to see my ID I thank them profusely for asking.
That's not the best thing to do and does nothing to prevent fraud and misuse. Actually, the card is not valid unless signed by the card holder so technically they don't even have to accept it. Also, Visa (and others) merchant agreements do not allow merchants to make presenting an ID a condition of sale. They can ask to see it but (generally) can't make it a condition of sale. But all that being said, most merchants and their salespeople don't know crap.