It is though. Take the example of the Books app on iOS. If you enable iCloud, it uploads third-party documents and books into its cloud - so far so good. If you

It is though. Take the example of the Books app on iOS. If you enable iCloud, it uploads third-party documents and books into its cloud - so far so good. If you discontinue iCloud (or even just disable the annoying upload-and-delete-local-copy for the Books app), every one of your books disappears, being held hostage by Apple. You literally have to then copy every single book that you bought elsewhere into the Books app again.