The five-man team operated with the help of a special remote they bought online and which could unlock a particular brand of gas pumps installed at Total gas stations.
The hack was possible because some gas station managers didn't change the gas pump's default lock code from the standard 0000. Hackers would use this simple PIN code to reset fuel prices and remove any fill-up limits.
Crooks would operate in small teams of two to three individuals who visited gas stations at night using two vehicles.
A man in a first car would use the remote to unlock the gas station, and then a second car, usually a van, would come along seconds later to fill a giant tanker installed in the back of the vehicle with as much as 2,000 or 3,000 litres in one go.
The group advertised the fuel they stole on social media, providing a time and place where customers could come and refuel their vehicles or pick up orders for gasoline and diesel at smaller prices.
Their scheme was uncovered in April 2018, when police arrested a suspect in Sagy, a Paris suburb. The suspect was in the possession of a remote at the time of his arrest. Five men, part of the same gang, were arrested on Monday, according to Le Parisien, who first reported the scheme last November.
The men were all in their 30s and 40s, had prior criminal records, and were from Val-d'Oise and Seine-Saint-Denis, two Paris suburbs. They only targeted Total gas stations across the Ile-de-France province surrounding Paris.
Authorities said the group made around €150,000 ($168,000) from selling the stolen fuel at a reduced price.
France has one of the highest fuel price levels in the EU. The Yellow Vests movement and subsequent protests that are still ravaging French cities started after a rise in fuel prices last November.
The scheme also became popular in the US. Last July, Detroit police reported similar incidents where thieves would use a remote device to unlock gas stations and make off with huge quantities of fuel.
Who is really in the driver’s seat? Unknown digital threats to your car’s security