The FBI Vault is a goldmine for those interested in the noir era:

http://vault.fbi.gov/

The section on popular culture is particularly fascinating. Just choosing personalities at random produces a whole wealth of fascinating intrigues - were Jack Benny and George Burns diamond smugglers for example? Did the Monkees submit their audiences to subliminal anti-war messages from a big screen? Was Lucille Ball, prominent actress and businesswomen, secretly (gulp!) a communist?


Lucille Ball - her red hair is a dead giveaway

More than anything, looking through the files illustrates the culture of irrational paranoia that permeated the FBI during the fifties and sixties - but surely that couldn't continue to be true today, could it?