I knew that the U.S. government kept files on John Lennon in the early 1970s, and that many of them were kept secret long afterward.
I didn't realize until just now that ten documents were still secret until this month -- and remained that way because the government believed disclosure could result in "military retaliation against the United States."
Jon Wiener has the story here. The documents are here.
Admittedly, letting our guard down regarding Lennon did result in multiple assaults by at least one foreign national on civilization itself.
But enough about Celine Dion singing "Imagine."