Chick-fil-A, one of America's most popular fast food restaurants, is the latest corporation to investigate the possible hacking of its customers' credit card data.
"Chick-fil-A recently received reports of potential unusual activity involving payment cards used at a few of our restaurants," the company said in a statement Wednesday.
"We are working with leading IT security firms, law enforcement and our payment industry contacts to determine all of the facts."
The company promised that if a security breach was confirmed, it would assume financial responsibility for fraudulent charges to customers' accounts, and arrange for free identity protection services -- including credit monitoring -- for any affected consumer.
With over $5 billion in annual sales Chick-fil-A, based in Atlanta, Georgia, is the biggest fast-food chicken restaurant in the United States.
US financial institutions have expressed alarm over data breaches affecting a growing number of American retailers.
"Unfortunately, 2014 has turned out to be the year of the data breach," said Dan Berger, CEO of the National Association of Federal Credit Unions.
Berger cited a massive data breach at Target a year ago, and the similar compromising of consumer information at retailers including Home Depot, Michaels Stores, Neiman Marcus, AOL, eBay and Staples.
"Congress must make passing a national data security standard for retailers a top priority when it returns next week," he said in a statement.
"Congress should hold retailers subject to the same national data security standards that apply to financial institutions."