posted on Nov, 9 2010 @ 03:23 AM
Top Secret Umbra is, or at least was, used in SIGINT for signal intercepts. The NSA is in charge of this area of intelligence gathering but the Army
Security Agency (now under a new name), Naval Security Group, and Air Force Security Squadron, operate intercept posts throughout the world. It may be
used for other purposes but I know it is/was used for this purpose. Everything that gets intercepted gets stamped UMBRA.