Credit card numbers, possibly stolen from Stillwater businesses, were being used nationwide and overseas Wednesday with charges in some cases reaching thousands of dollars.

"Right now there are several victims," said Police Chief John Gannaway. More people were calling his department Wednesday after Stillwater resident Ted Kozlowski posted a warning on Facebook that drew nearly 100 responses.

"It's a pretty widespread thing," said Kozlowski, a self-described Internet security guru who does Web marketing for a living. "There's a very large online black market for credit card numbers. They're absolutely untraceable."

Some victims said transactions in Spain and Russia had appeared on their bank statements. Others said they were seeing charges from restaurants, clothing shops, discount stores and gas stations in California, Texas, South Carolina, New Jersey, New York and New Hampshire.

Initial evidence showed the theft was related to credit cards used at the Mad Capper Saloon and Eatery on Stillwater's Main Street, Gannaway said. The chief said one of his investigators was looking into how customers' numbers were stolen.

"We're all frustrated because we can't figure out what's happening," said Mad Capper owner Jeff Chilson. "We're kind of getting the finger pointed at us right now, but it looks like it's ballooning out way more than us. I apologize to people, but it's not our fault."

Chilson said he knows of three other businesses where theft victims had used their cards.

Kozlowski said hackers could have invaded computers at companies that handle receipts from local businesses. The quick turnaround time for making fake cards and putting them to use suggests "this is a well-organized fraud," he said.

Merchant Card International, a Florida company that provides credit card processing services to businesses, inspected the Mad Capper's computers Wednesday and found them secure, said Lee Davis, the company's president.

"They came back clean," he said. "We're pretty convinced that the Mad Capper is not the main culprit here."

Gannaway said his department was trying to involve a federal agency with experience in credit card theft.

"This is a pretty complex deal obviously with the international implications," he said. "This will not be an easy case but we are going to work diligently."

Several people who posted on Facebook said their banks had stopped illegal charges on their cards.

At Lake Elmo Bank, customers were contacted beginning Tuesday when it was discovered that credit and debit cards were affected, said Christine Clark, the bank's vice president of marketing. "It was nothing the bank did. It was at the point of sale," she said.

Accounts at several other banks were involved, including TCF and Wells Fargo, according to Facebook postings.

One TCF customer, Gina Johansen of Marine on St. Croix, said she used a bank debit card at Mad Capper on Feb. 17. She discovered on April 3 that someone had made a $43 purchase and another for $200 at a Marshall's store in Upland, Calif.

"I don't understand how they can get access to all of this, the names attached to the numbers," Johansen said. "I'm worried about how the banks are going to deal with it."

Another Stillwater resident, Cheryl Kargel, said $900 in fraudulent charges appeared in her account after she paid for a meal at a fast-food restaurant last week. Charges includes three purchases at an online variety store, she said.

Kevin Giles • 612-673-4432