A "Pump & Dump" operation is busted in Gwinnett County.  Thieves were using stolen credit cards to buy gas then re-sell it at cut rate prices to truckers and smaller gas stations.

It is a multi-million dollar crime with a quick payoff!

"It's a very lucrative way to make money. It runs below the radar," says U.S. Secret Service Agent Steve Scarince.

Detective  Bert Ross with Lilburn police tells CNN  the gas thieves use vans or SUV's fitted with hidden tanks that can hold several hundred gallons of gas.

An alert gas station clerk tipped off police to this ring in Gwinnett after noticing the same man coming back day after day and spending more than 15 minutes at the pump each time. The investigation recently resulted in the arrest of five people. They have been charged with fraud, forgery and identity theft.