Just happened to me a couple of days ago. I'm always very careful when handing my card over at shops/restaurants, yet somehow someone was able to book 2 airline tickets on my credit card. Stopped card. Called Mango and Comair to cancel and refund. They both employ a couple of full time fraud investigators. Apparently it's done by syndicates. Whoever got your details in the first place, sells it to a syndicate, who buys tickets on your card and then sells them on to another poor guy... They airlines work with the banks and police to try and stop the syndicates, because there is no use arresting the person who pitches up at the airport.