Uber CEO Plays with Fire

How did they track these iPhones after the app was uninstalled?

They mention fingerprinting in the article.

Uber engineers assigned a persistent identity to iPhones with a small piece of code, a practice called “fingerprinting.” Uber could then identify an iPhone and prevent itself from being fooled even after the device was erased of its contents.

There was one problem: Fingerprinting iPhones broke Apple’s rules. Mr. Cook believed that wiping an iPhone should ensure customers that no trace of the owner’s identity remained on the device.

I expect what they do is fingerprint the device to detect fraudulent use later. Typically this is done by combining a bunch of identifiers and details on the device and then hashing the result. The output is a unique identifier for that specific device.

While technically this doesn't store any "identity" information on the device itself, if done correctly, the device could be identified and tracked across wipes (hence Cook's comment).

Of course, the article does a piss poor job explaining this, but for many readers the nuance doesn't matter... They capture the spirit well enough, even if the details are pretty misleading.

From the article, explained:

At the time, Uber was dealing with widespread account fraud in places like China, where tricksters bought stolen iPhones that were erased of their memory and resold. Some Uber drivers there would then create dozens of fake email addresses to sign up for new Uber rider accounts attached to each phone, and request rides from those phones, which they would then accept. Since Uber was handing out incentives to drivers to take more rides, the drivers could earn more money this way.

To halt the activity, Uber engineers assigned a persistent identity to iPhones with a small piece of code, a practice called “fingerprinting.” Uber could then identify an iPhone and prevent itself from being fooled even after the device was erased of its contents.

The American obsession with winning has definitely jumped the shark with Kalanick and Trump. At least I'm getting tired of all this "winning".

The article means "track" in the sense of "uniquely identify the physical device," not "send location information." Uber had code that would persistently identify which device was being used across two different installations of the app, even if the device had been factory-reset. (I suppose they could do something like find the MAC address, although Apple has been making that harder.)

Furthermore, that code wasn't triggered, somehow, in devices near Cupertino, indicating that they were trying to hide the code from App Store reviwers.

I think I feel that this is very qualitatively different from gathering location data on users who have deleted the app (if such a thing were possible), but nevertheless a serious ethical lapse.