Uber, which has recently been involved in a storm of controversy, was reported to have already been in trouble two years ago when Apple CEO Tim Cook threated to remove the ride-hailing service's app from the App Store.

The incident was revealed through an article by The New York Times that focused on Uber's likewise controversial CEO, Travis Kalanick.

Cook Reprimanded Kalanick In 2015 Meeting

According to the report by The New York Times, Kalanick met with Cook at Apple's headquarters in early 2015. The reason for the meeting was that Kalanick ordered Uber employees to implement a system in the service's app that violated the privacy guidelines of Apple.

"So, I've heard you've been breaking some of our rules," said Cook upon starting the meeting with Kalanick. Cook then demanded that Kalanick stop what Uber was doing, or else the company's app would be taken down from Apple's App Store.

Cook's threat against Uber was a heavy one. If the app would be removed from the App Store, it would no longer work with millions of iPhones, a move that may possibly bring down the company. Kalanick had no choice but to give in to Cook's demand.

What Did Uber Try To Do?

What was Uber doing that prompted such a serious threat from Cook?

It was reported that the Uber app had been secretly identifying and tagging iPhones, even after it was deleted and the smartphones completely wiped clean. By "fingerprinting" the iPhones with permanent identities, Uber was trying to prevent its drivers from cheating rides and claiming bonuses by accepting ride requests from fake accounts that they create.

What made matters worse was that Kalanick ordered his employees to hide the implemented system from Apple employees working in the company's headquarters. However, Apple workers working outside the Cupertino facility eventually found out about the fingerprinting, prompting the meeting between Kalanick and Cook.

Uber Responds To iPhone Fingerprinting Allegations

Uber, meanwhile, has responded to the report, stating that tracking is considered to be a common practice in the industry for preventing fraud and protecting accounts from being compromised.

Uber revealed that it is still using a form of device fingerprinting to prevent the app from being used in fraudulent ways, but Uber has modified it to comply with the privacy rules of Apple.

"We absolutely do not track individual users or their location if they've deleted the app," Uber reiterated in a statement.

Uber Controversies Piling Up

The reported meeting between Kalanick and Cook reveals another Uber controversy, which has not been in short supply recently.

Uber is currently embroiled in a legal battle with Waymo, the self-driving car unit of Alphabet, Google's parent company. The case recently took a turn for the worse for Uber as the company admitted that it discovered stolen Waymo files in the computer of one of its employees.

Last month, an Uber self-driving car was involved in a major accident in Arizona that caused the vehicle to flip to its side, raising questions on whether autonomous cars can already be trusted.

Uber board member Arianna Huffington said last month that the company needed to change, after the series of controversies that also included a heated exchange between Kalanick and an Uber driver and a reportedly toxic and sexist work environment.