Uber Technologies Inc. tracked iPhone users even after they deleted the app from their devices, and Uber tried to hide the practice from Apple Inc.’s engineers, according to a report by the New York Times.

Uber allegedly used a technique called fingerprinting to tag iPhones with unique codes that would allow the company to identify and track the devices after their app had been removed. This practice goes against Apple’s privacy policy, the New York Times says, so Uber tried to hide it by using geofencing to block engineers at Apple’s Cupertino, California, headquarters from spotting the code.

Unfortunately for Uber, Apple figured out what the ridesharing company was up to anyway, and Apple Chief Executive Tim Cook was not pleased.

“So, I’ve heard you’ve been breaking some of our rules,” Cook reportedly said to Uber CEO Travis Kalanick (pictured) during a face-to-face meeting. Cook demanded that Uber stop fingerprinting former users’ devices, or else Uber’s app would be booted from the App Store, an act that would deal a devastating blow to the ridesharing company’s business. According to the New York Times, Uber reluctantly complied.

Uber admitted in a statement that it uses fingerprinting to track devices, but the company says that this practice is used purely for fraud prevention.

“We absolutely do not track individual users or their location if they’ve deleted the app,” an Uber spokesperson said. “As the New York Times story notes towards the very end, this is a typical way to prevent fraudsters from loading Uber onto a stolen phone, putting in a stolen credit card, taking an expensive ride and then wiping the phone—over and over again. Similar techniques are also used for detecting and blocking suspicious logins to protect our users’ accounts. Being able to recognize known bad actors when they try to get back onto our network is an important security measure for both Uber and our users.”

The spokesperson made no mention of the claim that Uber had previously tried to hide its fingerprinting practice from Apple, and it is unclear if Uber had been forced to modify its code to no longer track users’ locations.

This is the second time this month that Uber has been accused of using software to illicitly track users. Earlier this month, a report by The Information claimed that Uber used a secret program called “Hell” to keep tabs on Lyft drivers.

Photo: Heisenberg Media [CC BY 2.0], via Wikimedia Commons