If ever you're in a restaurant, gas station, or anywhere that you might be using your credit card, keep your eye on it at all times.
It was reported that someone was in a restaurant paying for their meal with a credit card, the waitress came to their table, the patron gave the waitress his credit card, and she took it to the front counter to charge his meal for him.
While he was not looking, she exchanged the credit card for a false one and kept his credit card. This went unnoticed because the two credit cards looked exactly alike, and the patron did not notice that it was not his name on the credit card.