A juicy little story leaked out of Silicon Valley:  Apple CEO Tim Cook reportedly threatened to yank the Uber app from Apple's app store after discovering the ride hailing service trying to pull a fast one on customers.

According to a profile of Uber CEO Travis Kalanick in the New York Times, Uber's app contained a feature that allowed Uber to secretly identify and tag iPhone users even after the app had been deleted from users' phones.  The practice is called fingerprinting, and it's a violation of Apple's privacy rules.  Uber tried to sneak it through by "geofencing" Apple headquarters in Cupertino, changing its code so that it would be hidden from Apple Employees.  Apple engineers working outside Cupertino discovered it in 2015, and Cook didn't like it one little bit.  He called Kalanick in for a meeting.

"So, I've heard you've been breaking some of our rules," Cook reportedly told Kalanick in a calm tone.  Cook then threatened to delete Uber from the App Store if the company failed to stop the deception.  Losing access to millions of iPhone market would have been disastrous for Uber, so Kalanick complied.

In response to the NYT story, Uber said:  "We absolutely do not track individual users or their location if they've deleted the app."

But it wasn't the only time that Uber was caught with its fingers in some devious, underhanded stuff.  The company recently promised to change its ways after being caught using a secretive tool called "Greyball" to thwart efforts by local authorities to catch the ride-hailing company violating local regulations.  In 2014, an Uber executive allegedly used an internal feature known as "God View" to spy on a reporter's location without her consent.