2005 — Cardsystems Solutions Inc.: CardSystems was fingered by MasterCard after it…

CardSystems was fingered by MasterCard after it spotted fraud on credit card accounts and found a common thread, tracing it back to CardSystems. An unauthorized entity put a specific code into CardSystems' network, enabling the person or group to gain access to the data. It's not clear how many of the 40 million accounts were actually stolen.