Transcript for Credit Card Thieves Caught on Tape Using Skimmers
Vacationers be ware. Credit card scammers are setting up shop where you at least expect it. From fast food restaurants to gas stations. They're not actually stealing your card, just making it a target when you hand it over to pay. We've been investigating for months, and now one former criminal is switching side lgs. Here's ABC's nick watt for a series "Nightline" investigates. Reporter: You are watching a brazen breed of credit card thieves caught on tape. Miss it? Watch again. This McDonald's drive through attendant is swiping each card twice. Once to charge for the food, then another one to steal the info. Crooks can use that to spend a fortune. He got caught and pled guilty. Police say he was stealing up to 70 customers every single shift. They came in for a mcflurry, drove away with their bank info fleeced. But here's the thing, these electronic skimmers are so advanced they don't even need a human to operate. This alleged crook is searching for a skimmer device. It's stowed inside a gas pump in Arizona and left. It automatically steals your credit card info. This guy, caught on camera in a covert sting operation. He put those in there, for whatever reason, they're not there anymore. I know why. I have them. Reporter: He's the one who switched out that scanning device for a night vision spy camera. We may have the first-ever video of organized bad guys trying to retrieve their skimmers. Reporter: That's video gold. That's where I found mine, stuck up here. Reporter: Ahmed found a skimming device inside one of his pumps. He said he had no idea. It was stuck on one side to the metal. Reporter: Skimming all across the country has gotten so bad that the United States secret service, yeah, the same guys who protect the president, they are now on the case. Are you winning the war? It's even right now. We're doing our best. Reporter: They're getting help from police departments, tipoffs from gas station owners and wait till you meet one of their former secret weapons. Somebody turned my partner in and he turned me in. Reporter: Dan is a reformed hacker, who switched sides. He was caught by the secret service and spent two years training agents in the dark art of skimming. This is the reader that would be inside the gas pump. So you would just swipe it through and it would read it right here. Reporter: How do they get into those pumps? Believe it or not, there's a universal key that opens must gas pump doors. That's a universal key, the same key from Massachusetts to California. Reporter: You can buy one online. Only of the newer devices use cell phonal technology to transfer the data. Reporter: How much is my number worth? $5 to $30. Reporter: How do we stop guys like Dan from going on shopping sprees with your credit card infoe? The Arizona department of weighs and measures is trying to stop this high tech heist at its source. We're checking for skimming devices. Reporter: And they found a skimmer in this pump they had their right idea to lay a trap. They pulled out the skimmer and -- We inserted one of these little night vision spy cams in the back. Reporter: Here's the full video. 2:00 A.M. And a black SUV pulls into the gas station. Police say one fie block's the attendant's view and two people hunch over the pump. Here's the view from inside. Apparently a man and woman team caught red handed. We have the guy. Reporter: They can't find their skimmer and start bickering. It's almost like a husband and wife team arguing about where's the car key snls Reporter: The cops are still searching for them. So what can you do to protect yourself? Gas station owners are seeking new ways to protect their pumps. Here are some other things that you can do. Check your account. Most credit card companies will suck up any loss if you report it been 60 days. Choose wisely. Choose a pump near the attendant. Skimmers prefer to target pumps in the shadows. And pay inside. It's time consuming, but it's a whole lot safer. I'm nick watt for "Nightline" in Los Angeles.
This transcript has been automatically generated and may not be 100% accurate.