Two decades back, one of Vietnam's notorious mafia bosses was executed by a firing squad. Truong Van Cam, more commonly known as Nam Cam, or Vietnam's "Godfather," oversaw a vast criminal network that controlled much of Ho Chi Minh City's District 4. It was the ideal place for him to base his criminal activities: It's centrally located, buffered by waterways, and chock-full of clandestine networks of alleyways.