Several dozen more victims have come forward who bought gas in the Madera Ranchos and discovered their credit card numbers were stolen.
It's called skimming, when someone uses a device to read your credit or debit card's magnetic strip, without you knowing it.
Madera Rancho resident Dan Zumkeller discovered some $500.00 was stolen right out of his bank account, after he used his debit card to buy gas.
He's now changing the way he fills up.
Dan Zumkeller says, "We're going inside the store now, and watching our accounts more closely."
Elizabeth Hernandez says, "I got it $300.00 stolen and my daughter got it for $700.00 and the other was for $400.00 that's a lot of money and we are still trying to get it back from the bank."
Madera County Sheriff Department spokeswoman Erica Stuart says, "It's very serious, as a matter of fact I've never seen anything of this magnitude not in Madera County at least."
She says the crooks aren't stopping at the money they find in your bank accounts.
They're using the information to commit other types of fraud as well.
Stuart says, "They go open up bank accounts, buy cars they buy high end dollar stuff. They won't use your credit card, they will use it to change things, and then suddenly your name is appearing on things that you never had anything to do with."
Authorities think the thieves live in Southern California, where a number of high end items have been purchased in the last few months.
So far the thieves have hit a gas station in Tehachapi, one in Bakersfield, one in Tulare County, one in Fresno, and now the gas station along Avenue 12 in Madera County.
Deputies believe the device was placed on a Madera Rancho gas station pump from mid August through September. It was shortly after that victims said they noticed fraudulent charges on their accounts.
Best advice, if you must use your ATM or credit card, go inside the store.
These skimming devices are usually placed on the pumps at night when no one is around.
Another way you can protect yourself is to check your credit report from all three credit agencies at least 2 to 3 times a year, to make sure no new accounts were opened in your name.