Claim: Because of the rumors that a Japanese aircraft carrier was cruising off the coast of the San Francisco Bay Area, 500 United States Army troops moved into Walt Disney Studios lot to defend the Hollywood facility, and contributing to the paranoia was the fact that many  French merchant ships were attacked by Japanese submarines in waters off the West Coast.
Evidence: Rumors that a Japanese aircraft carrier was cruising off the coast of the San Francisco Bay Area resulted in the city of Oakland closing its schools and issuing a blackout; civil defense sirens provided by Oakland Police Department cars blared through the city, and radio silence was ordered. Contributing to the paranoia was the fact that many American merchant ships were indeed attacked by Japanese submarines in waters off the West Coast, especially from the last half of December 1941 through February 1942: SS Agwiworld (escaped), SS Emidio (sank), SS Samoa (escaped), SS Larry Doheny (sank), SS Dorothy Phillips (damaged), SS H.M. Storey (escaped, sank later), SS Camden (sank), SS Absaroka (damaged), SS Montebello (sank), SS Barbara Olson (escaped), SS Connecticut (damaged), and SS Idaho (minor damage).