Theft, the most obvious form of credit card fraud, can happen in a variety of ways, from low tech dumpster diving to high tech hacking. A thief might go through the trash to find discarded billing statements and then use your account information to buy things. A retail or bank website might get hacked, and your card number could be stolen and shared. Perhaps a dishonest clerk or waiter takes a photo of your credit card and uses your account to buy items or create another account. Or maybe you get a call offering a free trip or discounted travel package. But to be eligible, you have to join a club and give your account number, say, to guarantee your place. The next thing you know, charges you didn’t make are on your bill, and the trip promoters who called you are nowhere to be found.