Apple discusses who it uses for cloud storage when discussing iCloud in their security guide (valid as of May 2016): > The encrypted chunks of the file are sto

Apple discusses who it uses for cloud storage when discussing iCloud in their security guide (valid as of May 2016): > The encrypted chunks of the file are stored, without any user-identifying information, using third-party storage services, such as Amazon S3 and Windows Azure. [0]: https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf