“Golden 1 is proactively replacing all potentially impacted cards,” said Donna Bland, Golden 1 president/CEO. “The safety and security of our members' accounts is a top priority for us.”

Last week, NAFCU urged Congress to hold hearings on the data protection standards of merchants and how to strengthen them

The breach involved the theft of magnetic stripe data, which means criminals can use the data to manufacture new cards with valid magnetic stripe information that may lead to even more fraudulent activity.

The Missouri Credit Union Association in St. Louis said it has already contacted that state's U.S. senators and representatives regarding the data breach and the need for new legislation.

“We hope that the nationwide aspect of the Target data breach will provide an impetus for congressional action,” said Amy McLard, the MCUA's senior vice president of advocacy.

Dykstra suggested that retailers and financial institutions in the U.S. adopt the more secure chip and PIN card technology, noting its wide use in other countries and that it has proven to be far less vulnerable to security breaches.

“Every consumer now has to keep an eye on their credit information and there likely will be headaches for both consumers and the financial services industry, with the potential need to replace millions of cards,” she said. “It's an embarrassment for a retailer, but the breach costs fall on the shoulders of consumers and their financial institutions, like credit unions.”

Each card costs credit unions $5 to $10 to reissue and deliver. This expense is greatly exacerbated by the immense cost incurred by credit unions to reimburse their members who have lost funds due to fraudulent transactions, according to Dykstra.

“It's time to make sure retailers tighten the security of their systems,” Dykstra said. “A powerful incentive would be to hold them responsible for the cost of these breaches instead of consumers and financial institutions. This is a bipartisan issue our state and federal elected officials need to address.”

In Minneapolis, where Target operates its corporate headquarters, credit unions throughout Minnesota have been flooded with thousands of calls, emails and in-person contacts from members, the Minnesota Credit Union Network reported last week.

McCUN said credit unions were addressing member concerns, working with Target and card vendors and issuing new cards as needed.

The MCUA also said many Missouri credit unions are posting updates about the security breach on their social media sites.