The company originally created Greyball to protect its drivers from scammers and bogus riders. It is, after all, capable of determining if a request is legit by analyzing credit card and location data, among other info. Eventually, Uber used it to avoid authorities in places where it wasn't legally allowed to operate, including Portland, Oregon back in December 2014. The city conducted an investigation last week and found that Uber used Greyball to evade 16 transportation officials that month three years ago.

While the company now has to answer some uncomfortable questions in the midst of various other controversies, it's still unclear if it'll ever be penalized for the tool. Reuters says the DOJ is in the very early stages of its investigation, and a criminal probe doesn't necessarily mean that charges will be filed.