The retail trade groups also said retailers share some of the costs incurred by credit card fraud, citing a 2013 Federal Reserve study that examined debit card fraud instances. Retailers also contribute to the costs of issuing new cards to consumers after a data breach, the groups noted.

Merchants spend more than $6 billion each year on data security measures, the retailer organizations wrote.

They criticized credit unions for not adopting chip and pin technology within the timelines set by the financial industry.

In response to the letter, NAFCU President/CEO Dan Berger said, “We will join their partnership when retailers and merchants begin properly protecting consumers' data and investing in the technology necessary to do so.”

CUNA President/CEO Jim Nussle said data breaches at The Home Depot and Target have cost credit unions and their members a minimum of $90 million.

“With the many other breaches that have also occurred – at Staples, Neiman-Marcus and others – certainly credit unions have incurred millions more in costs this year,” he said in response to the letter.

A CUNA survey found that credit unions have not received reimbursements for the Target breach.

“In short, we'll back off highlighting the costs of data breaches on credit unions when merchants step up and take responsibility, adopt the same data standards, and stop making consumers vulnerable,” Nussle said.