An employee of Machine Zone, the developer of hugely popular mobile app Game of War: Fire Age, has been arrested after allegedly stealing trade secrets from the company. The Wall Street Journal reports that Jing Zeng, who worked as the firm's director of global infrastructure, was intercepted by FBI agents as he tried to board a plane to Beijing. A federal criminal complaint alleges that Zeng was trying to make off with information on the behavior of the game's millions of users, stolen from one of Machine Zone's internal databases.

Zeng joined Machine Zone in 2014, but reportedly became unhappy in his position by spring, and asked to change teams. His request was denied and his superiors asked him to leave the company, at which point it's alleged he started to download the data, which among other things, specified how users spend money in the game. The Wall Street Journal says that Zeng then tried to use the data as a bargaining chip to secure himself a bigger severance payment when he was confronted by his colleagues.

While the information wouldn't compromise player details or payment information, the criminal complaint alleges the data Zeng downloaded could "provide valuable insight and a huge competitive advantage over other online game providers and competitors." Game of War: Fire Age is one of the highest-grossing apps in the world, giving Machine Zone enough money to run $40 million advertising campaigns first with model Kate Upton, and more recently with Mariah Carey. Any behind-the-scenes information player habits would undoubtedly be useful for the company's rivals, but the federal complaint doesn't detail whether Zeng had further plans for it beyond acting as collateral.