All of the hoopla surrounding last week’s inauguration almost completely overshadowed a huge information breach that occurred at a Princeton, New Jersey credit card processor’s computer network. In fact, this may just rank as the biggest data breach in history and involved over 100 million transactions.

Heartland Payment Systems, Inc., reported that card numbers, expiration dates, and internal bank codes were improperly accessed. No SSNs, encrypted PINs, addresses, or telephone numbers were accessed.

Heartland processes 100 million Visa, MC, AmEx, and Discover Card transactions per month for over 250,000 businesses across the country. The merchants involved and how may customers were involved was not disclosed.

This makes it impossible for consumers to know if they have been affected by this breach. For this reason, everyone should pay extra attention for signs of any unauthorized charges on credit cards and for new accounts being opened in their name.