There was a static universal device identifier until iOS 6. Even today, while Apple has implemented many sensible restrictions on tracking, there's still a ton

There was a static universal device identifier until iOS 6. Even today, while Apple has implemented many sensible restrictions on tracking, there's still a ton of information that can be used for device fingerprinting freely available to all apps. This blog post [0] pegs the amount of useful information at around 56 bits. [0]: https://nshipster.com/device-identifiers/#fingerprinting-in-todays-ios https://nshipster.com/device-identifiers/#fingerprinting-in-...