Submitted by SpiritThing78 t3_zy88uz in iphone
Many times people sent me links to posts on Facebook or their Facebook profile links, but these links always open in browsers, not the Facebook app. A comment on Reddit said I should delete the Facebook app and its data and then reinstall the Facebook app, then this problem will be solved (https://www.reddit.com/r/ios/comments/eoky1x/comment/fitmeie/ ). Many people upvoted and agreed with that comment. So I decided to delete my Facebook app and its data.
I know the difference between deleting an app (and its data) and offloading an app. I deleted the Facebook app, and then I reinstalled it but all my previous logged-in accounts automatically appear again. Why is that? Isn’t all data about these accounts deleted? Many people meet the same issue as me but no one can explain it, for example: https://discussions.apple.com/thread/253081117
Not only that, in the game Homescapes, even when I do not log in or back up my progress with Apple, Google, or Facebook, when I delete the game and reinstalled it, the game progress is automatically restored.
Facebook and Homescapes are the two apps that I cannot delete their related data. I think Apple shared my Apple ID with Facebook and other apps (such as Homescapes) so that when I reinstalled Facebook from App Store, Facebook recognized my Apple ID and placed back my three Facebook accounts. It makes me frustrated, I don’t want anyone to know I have three Facebook accounts. Is what I guess true?
freaktheclown t1_j24ccn9 wrote
Apple didn’t share your Apple ID. What’s happening is that apps can store data in the Keychain. Usually this would be login credentials, but they can also store other data, such as a token or some other identifier, that will allow the behaviour you’re seeing. Deleting an app doesn’t delete Keychain data. If you turn on iCloud Keychain then this data will be synced through iCloud.
On iOS, you can only see app and website passwords in the Keychain. On a Mac, you can see all data in the Keychain using the Keychain Access app. Just checked mine, and as an example, there are things like
com.instagram.users.persistent_accountsandcom.google.sso.GeneratedDeviceIdentifier(although it doesn’t look like you can see the actual data inside these). Things like that are what allow apps to retain info.