Mac Users’ Unsaved Files and Screenshots Are Automatically Stored on iCloud (slate.com)

This is will be a nice but must encrypted (transparent and fast) on the client side.

Hey Folks. Thomas from IDrive online backup. I just wanted to point out that IDrive never automatically backs up your files unless you turn on Continuous Data Protection. We also offer private key encryption so the files you backup can only be accessed by you. This is a much securer online backup option.

If you turn off iCloud, all documents stored in iCloud will be deleted from this Mac. http://imgur.com/YcWPjnk