One customer has already had his or her information stolen, and investigators are looking for other possible victims.
If you went to the Mobil station in the 5300 block of Baldwin Avenue last month, Los Angeles County sheriff's investigators say check your transactions.
Employees found skimmers that had been recording credit and debit card numbers, including pins and zip codes, for at least a week. Deputies seized two devices from two separate gas pumps.
If you see someone suspicious tampering with gas pumps at any gas stations, you're asked to call the sheriff's department at (626) 285-7171.