Although he was a notable oil industry magnate and received widespread coverage when he married the Denver Post heiress 40 years his senior (after previously working as her chauffeur), Mike Davis was best known at the time of his death as the "World's Grumpiest Boss," after his 1970s-era office memos banning "levity" and even unsolicited greetings circulated online. His FBI file captures yet another facet of his life, documenting over some 200 pages a dramatic $50,000 Las Vegas extortion attempt of which he was the victim, and which involved Frank Sinatra and a number of famous casinos.

New York Times obit: Mike Davis, ‘World’s Grumpiest Boss,’ Dies at 85