In 1944, the CIA's precursor, the Office of Strategic Services (OSS), distributed a secret pamphlet that was intended as a guidebook to citizens living in Axis nations who were sympathetic to the Allies.

The "Simple Sabotage Field Manual," declassified in 2008 and available on the CIA's website, provided instructions for how everyday people could help the Allies weaken their country by reducing production in factories, offices, and transportation lines.

"Some of the instructions seem outdated; others remain surprisingly relevant," reads the current introduction on the CIA's site. "Together they are a reminder of how easily productivity and order can be undermined."