Apple CEO Tim Cook once personally threatened to kick Uber out of the App Store

Apple CEO Tim Cook once personally told Uber CEO Travis Kalanick that the Uber app violated Apple's privacy rules, and threatened to remove Uber from Apple's App Store, the New York Times reported on Sunday.

The issue in the reported early-2015 meeting was that Uber was tracking iPhones after they had been wiped and the Uber app had been deleted - something Uber was doing to combat driver fraud in China.

Apple didn't like that, and believed it violated its privacy policy for the App Store. "So, I've heard you've been breaking some of our rules," Cook reportedly told Kalanick.

If Apple were to stop carrying the Uber app, the multi-billion dollar startup would lose access to millions of its most valuable customers.

In fact, Uber went so far as to write software that ensured that anyone accessing Uber from Apple's headquarters would see a different version of the app without the bits of code that tracked iPhones after they had been wiped, a practice called "geofencing."

But Apple engineers were able to spot that something wasn't right with the Uber app at Apple headquarters, and escalated the issue, which led to the meeting between Kalanick and Cook, according to the Times.

Kalanick was reportedly "shaken" by the meeting with Cook, but the relationship between the two men and companies seems fine today. Cook and Kalanick were spotted mugging for the camera together at last year's Met Ball, for example, and the Uber app is still available on Apple's App Store.

The entire profile of Travis Kalanick by the New York Times' Mike Issac is absolutely worth a read.