
Ask HN: How does the Twitch iOS app keep me logged in after reinstalling it? - holidaytrucksky
I thought that deleting an iOS app would delete all data related to that app. How does the Twitch app still know my account after I delete it and instal it again?
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solumos
Uber got in Big Trouble for this a while back[0]. Basically, device
fingerprinting[1]. It seems like it's sort of OK now?

[0] [https://the-parallax.com/2017/04/26/uber-device-
fingerprinti...](https://the-parallax.com/2017/04/26/uber-device-
fingerprinting/)

[1] [https://nshipster.com/device-identifiers/](https://nshipster.com/device-
identifiers/)

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searchableguy
Slightly related, I was able to take over an account with functionality
similar to this in one of the apps from a big tech company recently. I
reported it but no response so far.

Are there companies using unique fingerprinting methods to map users for
faster logins? I didn't test it further. It happened accidentally.

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neximo64
Apple keychain

