Whether a piece of information is private, proprietary, or sensitive to national security, systems owners and users have little guarantees about where their information resides or of its movements between systems. When a user enters information on a phone, for example, it is difficult to provably track that the data remains on the phone or whether it is uploaded to a server beyond the device.
The national defense and security communities are similarly left with few options when it comes to ensuring that sensitive information is appropriately isolated, particularly when it's loaded to an internet-connected system.