Dunno if Greenwald has any evidence he hasn’t yet shown, but I ran across this USAF solicitation from early 2011 that I kept for posterity. You tell me what the USAF was going to use this for. Note, link no longer works; afaict the FBO’s live database only goes back a year.

fbo.gov

Persona Management Software.
Solicitation Number: RTB220610
Agency: Department of the Air Force
Office: Air Mobility Command
Location: 6th Contracting Squadron

Excerpt:
0001- Online Persona Management Service. 50 User Licenses, 10 Personas per user.

Software will allow 10 personas per user, replete with background , history, supporting details, and cyber presences that are technically, culturally and geographacilly consistent. Individual applications will enable an operator to exercise a number of different online persons from the same workstation and without fear of being discovered by sophisticated adversaries. Personas must be able to appear to originate in nearly any part of the world and can interact through conventional online services and social media platforms. The service includes a user friendly application environment to maximize the user’s situational awareness by displaying real-time local information.