The Audubon Police Department is warning debit and credit card users that their card information may be compromised after the discovery of a skimmer on a gas pump. Authorities discovered the device Friday at the Yesway Convenience Store in Audubon. Skimmers are placed fraudulently by thieves near card readers on gas pumps, cash registers and ATMs. The skimmer reads your card’s information and relays it to a different location to be used illegally. The U.S. Secret Service estimates nearly $1 billion are lost to card skimmers every year. If you have used a card at the Yesway, the Audubon Police Department recommends monitoring your account for suspicious activity. Contact your financial institution and the police department at 712-563-2500 if you suspect fraud has occurred.