Anyways, it seems like the NSA feel it is copyrighted: http://gawker.com/the-nsa-sent-a-takedown-notice-over-my-cus...
Had they done so, it'd presumably be a work for hire and still not be copyrightable, since the government would own it.
“Unlike works of the U.S. Government, works produced by contractors under government contracts (or submitted in anticipation of such contracts) are protected and restricted under U.S. copyright law.”
Also important: even if a federal employee made it, it may not be protected by copyright in the US but it can still be copyrighted in all other countries.
http://en.wikipedia.org/wiki/Copyright_status_of_work_by_the...