12 million Uber uses were compromised in 33 government requests to view the data which Uber holds. Uber has published this in their transparency report which can be found at their website.
They state that regulated transportation companies are forced to share information with government agencies;
Regulated transportation companies are required by law to provide certain information about their operations to local regulatory agencies. These agencies may request information about trips, trip requests, pickup and dropoff areas, fares, vehicles, and drivers in their jurisdictions for a given time period.
In the picture below, you can view the amount of requests which were made by government agencies in order to view the whereabouts of Uber drivers.
The drivers/users which were affected were located in the following cities/states;
In the following picture, you will see that 613 requests were made by government agencies in order to get a closer look at possible suspects which were using or providing the Uber taxi service.
Uber stated that;
Uber receives law enforcement requests for information related to criminal investigations, and may provide information about specific trips, riders or drivers in response.
Read the official report here.