Uber tracked drivers from rival Lyft with a program called Hell. This is reported by The Information.
The program allowed tracking the movements of Lyft drivers and the prices at which they work. Uber was also able to identify drivers who worked for both companies and subsequently poached them by sending them more orders and rewarding them with bonuses.
To spy on competitors, Uber created fake accounts in Lyft, which the system of this service took for real. The accounts fed false location data to Lyft of non-existent drivers, allowing Uber to see where the real drivers closest to that point were.
Only a few people knew about the existence of the program, including the head of Uber, Travis Kalanick. The company used it from 2014 to early 2016, according to The Information.