For a number of iOS-specific functions, the infrastructure operated by Apple must be used. If iCloud Keychain, iMessage, FaceTime, Siri, Continuity, Spotlight Suggestions, or iCloud functions for creating backups or working jointly on documents are used, the corresponding data is constantly synchronised among different devices and users via Apple's infrastructure. Push messages for iOS-based devices are also transmitted via this infrastructure. There is therefore a general risk that Apple servers will be accessed and the data stored or transmitted there will be misused for other purposes.