PITTSBURGH (KDKA) — The security breach at Target was massive — $40 million debit and credit card accounts hacked.

“I had heard about it, and I thought naïvely that I wouldn’t be affected,” said Tom Buell, a Target breach victim.

READ MORE: St. Patrick's Day Parade In Pittsburgh Sees Smaller Crowd For Celebrations In September

Buell was one of the unlucky ones. His bank called to say his card had been compromised and cancelled.

KDKA’s Susan Koeppen: “How was your data used?”

Buell: “They said that at a 7-Eleven in Florida someone tried to make a $58 purchase and they flagged it because I had just had lunch in Pittsburgh.”

So, how did Buell’s debit card information get from a breach at Target to a crook using it a 7- Eleven? All of that stolen information is now up for sale on the black market.

Nicolas Christin is a cyber-security expert at Carnegie Mellon University.

Koeppen: “How many credit card numbers are for sale right now online?”

Christin: “We are talking dozens of millions at least.”

He showed just one site where stolen credit and debit card numbers are the commodity.

Koeppen: “So all of these cards you are scrolling are issued in Pittsburgh?”

Christin: “In Pittsburgh.”

READ MORE: Male Suspect In Custody After 3 People Shot At Baby Shower At Kinloch Volunteer Fire Department

Koeppen: “And they are all stolen and up for sale?”

Christin: “All stolen and up for sale.”

There were thousands of them – Visa, Mastercard, Amex – from banks like PNC, Huntington and Dollar.

Christin: “This is filling up already six pages.”

Koeppen: “Six pages of credit cards?”

Christin: “Six pages of credit and debit cards just from Pittsburgh.”

Your personal information may be priceless to you — but on this site — your debit card is selling for about $20. It was on a site like this where someone bought Buell’s data.

“It’s mind boggling,” said Buell. “I guess you can buy anything on the Internet now; and credit card numbers are just another commodity.

There’s not much consumers can do to avoid becoming a victim of a breach – anyone who shops with plastic is at risk.

“Long story short. The cash register got broken into,” said Christin. “How can you protect against that as a user? You use cash, that’s all you can do.”

More News on the Target Breach
More Consumer News
More Reports by Susan Koeppen

MORE NEWS: Allegheny Co. Police Investigating After Woman Found With Gunshot Wound In City Of Duquesne

Join The Conversation On The KDKA Facebook Page
Stay Up To Date, Follow KDKA On Twitter