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…
Basically, they created a unique 'fingerprint' of the iPhone. It was unique enough that even if you reinstalled the app, the fingerprint would still be the same. This was done, ostensibly, to prevent people from scamming them by reinstalling the app and coming over as new users? But they already have the phone number, so I don't understand the point.