Protect your credit card information by using an unactivated credit card for authentication. Many places such as hotels will use your credit card as a second means of identification.
Credit cards are not swiped for any financial transaction, but may be photo or carbon copied to protect the owner in case you destroy something or decide to jet.
By using an unactivated travel credit card, you’ll have the plastic to show but won’t have to worry about a shady car rental employee from buying a Prada bag with your Visa. Just make sure to peel off the activation sticker before you hand it over.