Government Attic used the Freedom of Information Act to force the NSA to cough up its "old security posters from the 1950s and 1960s"; after two years' delay, the NSA finally delivered 139 pages' worth of gorgeous, weird, revealingly paranoid internal materials, produced by an incredibly prolific internal security office who constantly refreshed their poster designs (presumably to keep them from disappearing into the background), all funded with US public money and thus in the public domain for your remixing pleasure (a few dozen of my favorites below!).