Portland is done investigating Uber's use of the infamous 'Greyball' tool in the city. The results? According to Reuters, authorities have discovered that the ride-hailing service used the software to prevent 16 of the city's regulators from booking rides. It also ignored and canceled 29 ride requests by city transportation enforcers. Uber's Greyball scheme first came to light when The New York Times revealed in March that it has a tool that can block known authorities from booking rides and even seeing if there are cars available in the area. The service used that tool to be able to operate in areas where it had no permission to do so, including Portland, Boston, Paris and Las Vegas.