Three Colorado Safeway stores were the target of thieves recently, after officials found card skimmers in credit card checkout pin pads at each store location.
Employees discovered the skimmers during routine inspections in November, according to Safeway spokeswoman Kris Staff.
Staaf said skimmers were found at stores in Denver on W. 44th Avenue and Lowell Blvd., Lakewood on W. Colfax Avenue and Garrison St., and the Conifer location on Main Street.
Metro State Security Expert Steve Beaty said skimmers are becoming more sophisticated, which is making it harder for consumers to protect themselves.
"[It's an] especially hard problem with things like debit cards and ATM cards because they're not currently using the pin technology," he said.
Beaty added that compromising a credit card checkout terminal is a lot more difficult than targeting ATMs and gas station pumps, which are common targets for thieves.
"You have to be on premise and have to do it quickly, if it's not somebody who's doing it who has continuous access to these devices," he said.
Staaf said Safeway used surveillance video to figure out exactly when the skimmers were installed. She also said they were able to pinpoint how often the devices were used and contacted those customers as well as police.
"Customers who have any concerns should review their bank statement for fraudulent activity in November, or contact their cardholder or bank directly," Staaf said in a statement.
She also stressed that these are rare discoveries.
Skimmers were also found at two other Safeway stores in Northern California.