They’re helpful. They’re conveniently located. And they spit out your money in $20 bills. But the Santa Barbara County Sheriff’s Dept. is warning residents to be wary of a locally based scam that uses automatic teller machines (ATMs) to rob customers of their savings.

The scam involves the insertion of an adhesive strip into the card slot, making customers’ cards stuck. A placard the thieves place on the ATM instructs the customer to enter his or her personal identification number (P.I.N.) three times in order to release the card. However, repeatedly entering the P.I.N. only allows nearby thieves to memorize the P.I.N. for their own illegal use after the customer has left without having been able to free his or her card.

Three Bank of America ATMs have been used in the scam: one in Oxnard, one in Ventura and one on the 4800 block of Hollister Avenue. All three incidents happened between Feb. 9 and 15. No similar scams outside of the area have been reported.

Sheriff’s department spokesman Sgt. Chris Pappas said aside from recognizing the circumstances of the scam, bank customers should always exercise caution when using ATMs.

“Should people see a placard telling them to punch in their P.I.N. three times, it should immediately arouse their suspicion,” Pappas said. “There’s no way a bank would ever ask people to punch their P.I.N. three times if there was a problem with the ATM.”

So far, only Bank of America has reported its ATMs being used in the scam. Ken Preston, the bank’s vice president, said the bank is working with the sheriff’s department to stop the scam.

“Consumers should be aware,” Preston said. “P.I.N.s are private. … Customers should not be entering them for any purpose other than the proper procedure.”

Preston said although theft is a crime that customers should try to prevent, financial loss due to illegal ATM withdrawals may be recovered.

“If something like that happens, [a customer] should go into the bank and ask to speak to the manager,” he said.

Pappas said anybody who observes any of the elements of this scam on an ATM should notify the police and call the bank at once.

“Call the police and talk to the bank manager,” Pappas said. “The matter should be taken care of right away.”

No representatives of any other bank were available to comment on whether the scam had been attempted on their banks’ ATMs.