When you pull up to the pump, you've usually got plenty on your mind. Thoughts of where you need to drive next, how much the gas costs, and how late you're going to be now that you had to stop all run through your mind as you fill up your car. But there could be a much more sinister threat waiting for you at the pump.

They're called card skimmers. Thieves install them at the pump to steal your credit card information, and they're almost impossible to spot.

"The one's that we're seeing now are inside the cabinet, you can't see them," said Georgia Department of Agriculture Director of Fuel and Measures Richard Lewis.

They're hidden, waiting for you to enter your card. When you do, that skimmer will collect and store the information from the card's magnetic strip. On some newer models, thieves don't even need to come back to pick up the data. The skimmer can transmit it by Bluetooth as far as a mile away. Once they have that information, they can use it to make fraudulent charges on your card.

Bibb County Sheriff's Office Investigator Dennis Terry calls it a widespread problem.

"Skimming is a multi-billion dollar industry and this has been happening all over the country."

Here in Georgia, at least fifteen skimmers have been found since 2015, and six of them were located in central Georgia. Four were spotted in Unadilla, one in Juliette, and one at a Chevron station in Macon in November. The Department of Agriculture director who oversees gas pump inspections says just one can do serious damage.

"It could get hundreds of cards in just a few days," said Director Richard Lewis.

He concedes that there are likely more out there, too.

"I feel pretty sure there probably are."

We talked to River Vaughn while he was filling up. He said he's never been skimmed but it's a risk he's aware of.

"It messes up your whole attitude I feel like, especially around the holidays and people are trying to save up," said Vaughn.

Card skimmers aren't just a risk for customers, either. Ash Patel owns and operates a single gas station across from the Chevron in Macon that was skimmed. He says that it's a threat to his business, too.

It's just one of those things that you don't have control over it. You did not do it intentionally. There is somebody else who did this, but then you'll have to pay for it since you're going to lose all the customers."

To keep your information safe, there are some steps you can take to limit your risks.

The Department of Agriculture says that you should at least be sure to use a credit card instead of a debit card while getting gas. If possible, they say your safest move is to just pay with cash.

Department of Agriculture inspectors also say to examine the card reader at the pump before entering your card. If it seems loose, it may have been tampered with.