The NSA is actually it's own layer in the OSI model. They won't teach you about this in school, though, but there are even more than 7 layers.... /s

I always found it very awkward working in 111 8th Ave and seeing "National Security Agency" on the building directory. It's like we weren't even pretending what was going on there.

(My greatest enjoyment, however, was that Level 3 was on the 3rd floor.)