Controversial transportation network Uber could be in hot water yet again after allegedly using a secret software to keep an eye on its ride hailing rival Lyft between 2014 and early 2016. A move that could result in the company facing many a legal case.

According to The Information, Uber exploited a vulnerability in Lyft’s system to enable it to use its ‘Hell’ software – because the  tracking software for their own drivers and passengers was called ‘God’s View’ or ‘Heaven’.

In order to take Lyft to Hell, Uber created fake Lyft rider accounts. These fake accounts tricked the system into thinking they were in locations around the city, and in turn presented each of the fakes with information regarding ‘their’ eight nearest drivers.

In watching over its rival, Uber discovered that Lyft’s drivers are identified by special numbered IDs that don’t change – thus allowing Uber to learn each driver’s habits and figure out which drivers operated for both Lyft and Uber.

With the information it discovered, Uber began trying to entice drivers who used both platforms to solely use their app. To do this, Uber began sending double drivers more riders than to those that only operate on Uber, as well as giving them bonuses when they met a certain number of riders per week.

The Hell program was eventually stopped, after already forking out millions to drivers, when Lyft started expanding to more cities.

A Lyft spokesperson told The Information: “We are in a competitive industry. However, if true, these allegations are very concerning.”