You might have read about it already but i wanted to share with you some historical interesting news concerning Pearl Harbour.
Craig Shriley's book reveals a 20 page memo from FDR's declassified FBI file, the Office of Naval Intelligence on
December 4 warned, "In anticipation of open conflict with this country,
Japan is vigorously utilizing every available agency to secure
military, naval and commercial information, paying particular attention
to the West Coast, the Panama Canal and the Territory of Hawaii."
You can read some more about it here.
The preface of the book is available from the author's site.
Podcasts with the author are available here and here.