Now that you have a space in your cloud to put all your videos, you can come up with much simpler plans for multi-level security in that cloud using technology means that have been thoroughly vetted for decades. Better results with less technology burden. This can solve nearly any of your needs, not only the just-in-time requirements driven by the popularity of personal video production and sharing. Certainly every unclassified activity is covered and that alone makes the world better by several orders of magnitude. But, replicate this model on NIPR, SIPR, and JWICS and every possible thing you could want to do with digital video will be covered by (roughly) the same technology solution. People who have to manage security layers will still have to manage security layers, but that concern is more easily separated from the entanglements of technology now. This is a good thing all around in ways I hope and think you realized before I ever commented here.
More thoughts on Federal Agency Internet Utility Model.
P.S. "OneSource" is a bad term. When it comes to shared content, there is never one source. That's the point. You are the infrastructure, just need to figure out how to make that catchy for PR and marketing. One Destination, maybe. ...needs work in any case.