Apple Copies Your Files Without Your Knowledge or ConsentThe latest version of Apple's OS automatically syncs your files to iCloud Drive, even files you choose to store locally. Apple encrypts your data, both in transit and in iCloud, with a key it knows. Apple, of course, complies with all government requests: FBI warrants, subpoenas, and National Security Letters -- as well as NSA PRISM and whatever-else-they-have demands.
This is a more nuanced discussion of this issue. At this point, it seems clear that there is a lot less here than described in the blog post below.
There is something here. It only affects unsaved documents, and not all applications. But the OS's main text editor is one of them. Yes, this feature has been in the OS for a while, but that's not a defense. It's both dangerous and poorly documented.