It should come as no surprise to anyone that Apple takes the privacy of its iPhone users very seriously.

This is after all the company that famously resisted FBI demands for a backdoor into a terrorist's iPhone. So it was understandable that Uber CEO Travis Kalanick might have been a bit anxious before a 2015 meeting with Apple CEO Tim Cook.

The reason? Kalanick had been directing his engineers to camouflage a feature in the ride-hailing app that allowed Uber to secretly identify and tag iPhone users, even after the app had been deleted from users' phones, according to a wide-ranging profile published Sunday by The New York Times. But Apple was on to the ruse, which violated Apple's app privacy rules.

"So, I've heard you've been breaking some of our rules," Cook reportedly told Kalanick in a calm tone. Cook then demanded Uber stop the deception or face getting yanked from Apple's App Store.

Losing access to millions of iPhone users would destroy Uber's business, so Kalanick complied with Cook's demand, the newspaper reported.

Uber denied using its app to track individual riders' locations, saying the feature was used for fraud detection.

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

This isn't the first time Uber has been accused to using software for nefarious purposes. The company was recently caught using a secretive tool called Greyball to thwart efforts by local authorities to catch the ride-hailing company violating local regulations. The company has since said it would stop using the tool for that purpose.

In 2014, an Uber executive allegedly used an internal feature known as "God View" to track a reporter's location without her knowledge. Uber's use of the tool, which allows employees to see logs of Uber customer activity, suggested "a troubling disregard for customers' privacy," Sen. Al Franken, chairman of the Subcommittee On Privacy, Technology and the Law, said in a letter to the company.

The resulting backlash led the company to hire a third-party data-privacy expert to review its policies and provide recommendations.

It wasn't immediately clear if Kalanick's meeting with Cook in 2015 was about the "God View" tool.

Representatives for Apple didn't immediately respond to requests for comment.

Updated at 11:35 a.m. PT with Uber comment.

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