The NSA is building a private cloud with its own security features:

As a result, the agency can now track every instance of every individual accessing what is in some cases a single word or name in a file. This includes when it arrived, who can access it, who did access it, downloaded it, copied it, printed it, forwarded it, modified it, or deleted it.

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“All of this I can do in the cloud but–in many cases–it cannot be done in the legacy systems, many of which were created before such advanced data provenance technology existed.” Had this ability all been available at the time, it is unlikely that U.S. soldier Bradley Manning would have succeeded in obtaining classified documents in 2010.