NYTimes published interesting article on security at Visa in light of the CardSystems fiasco that happened two months ago. In that incident the personal information of over 40 million people has been hacked. The hack occurred at CardSystems Solutions, a company that processes credit card transactions.
Visa, like the other major credit card companies, has managed to reduce financial losses stemming from fraud, but it continues to struggle with preventing the theft of card data in the first place. Indeed, policing the payment chain is a herculean task, because virtually every step is outsourced from the time a card is swiped to the time the monthly statement arrives.
Read more at: https://www.nytimes.com/2005/08/25/business/25visa.html