On Tuesday, 13 men were charged in a case involving Bluetooth-enabled data skimmers planted on gas station pumps. The hackers allegedly made more than $2 million by downloading ATM information from the gas pumps, and then using that data to withdraw cash from ATMs in Manhattan.

According to Manhattan District Attorney Cyrus R. Vance, the suspects used credit card skimming devices that were Bluetooth-enabled and internally installed on pumps at Raceway and Racetrac gas stations throughout Texas, Georgia, and South Carolina. Because of this configuration, the skimmers were invisible to people who paid at the pumps, and later, the suspects were able to download the skimmed data without physically removing the devices.

Between March 2012 and March 2013, the suspects used forged credit cards to withdraw money at ATMs around Manhattan and deposited the cash in New York bank accounts, feds say. Then, other members of the group withdrew the money from those bank accounts in California or Nevada.

"Each of the defendants’ transactions was under $10,000,” wrote the Manhattan District Attorney's office. “They were allegedly structured in a manner to avoid any cash transaction reporting requirements imposed by law and to disguise the nature, ownership, and control of the defendants’ criminal proceeds. From March 26, 2012, to March 28, 2013, the defendants are accused of laundering approximately $2.1 million.”

Four of the 13 men—Garegin Spartalyan, 40, Aram Martirosian, 34, Hayk Dzhandzhapanyan, 40, and Davit Kudugulyan, 42—are considered lead defendants and are charged with money laundering, theft, and possession of a forgery device and forgery instruments. The other men are each charged with two counts of money laundering.