Rene Ritchie, iMore:
Apple has posted its Report on Government and Private Party Requests for Customer Information for the second half of 2016.
The TL;DR of it is that demands on the data being stored on our iPhones, iPads, and Macs are, unsurprisingly, up.
In this context, it’s important to remember that while Apple protects messages and other personal data with end-to-end encryption, Apple has to turn over iCloud backups when and if required to do so by law.
Unlike local backups, no option is available to encrypt iCloud backups. Possible technical hangups notwithstanding, I’m surprised that’s something that hasn’t yet been made available in iCloud. If iMessages are worth encrypting in transit, surely they’re worth encrypting in a backed-up state as well.
Update: Well this is embarrassing. Via Laurent Boileau, it appears that iCloud backups are, indeed, encrypted (page forty-one of that PDF). Past Apple documentation claimed that device backups in iCloud were encrypted, but that didn’t include some user data like Notes, iMessages, and SMS messages. I don’t know why I didn’t verify this before posting, but I apologize for the error.