USA Today explains:
Under the upcoming policy, the Uber app could collect precise location data about a customer's smart phone, even when the app is running in the background or they have turned off their GPS location finder.
If the app isn't on, Uber can figure out the user's approximate location from their Internet address.
If the user permits it, the Uber app can access the user's address book and use the names and contact information it finds there.
The full USA Today story is here.
The EPIC complaint is here.