Another mega breach headlines last week.  Though no one can say yet what happened, as usual the press statements offer some possibilities.

What is the most important clue?  Visa and Mastercard claim (in their warning to banks) that the full Track data from the card was obtained. This is an interesting piece of information as Track data is not available for web based transactions.  In fact, Track data is only available when the credit card is swiped. It means that the source of the data is point-of-sale devices rather than Internet transactions.  

What about PCI compliance?  Track data storage is forbidden according to PCI-DSS. So either Global Payments are not in compliance with PCI-DSS or the attackers were able to sniff transactions over a network.