The “Soylent Green is people” cable easter egg is a long-running Central Intelligence Agency case-officer in-joke in which the line “Soylent Green is people” is hidden inside operational cables as an arrangement of incongruously lowercase letters.[1]
Mechanism
CIA cables are, by convention, written exclusively in capital letters — a typographic norm carried forward from the agency’s 1950s teletype-era infrastructure that has never been updated. “It’s like some thing from the 50s. They just never changed it.”[1]
This convention makes any lowercase letter visually anomalous. Case officers writing the obligatory blow-by-blow, minute-by-minute account of an operational meeting would scatter individual lowercase letters through the otherwise all-caps text such that the lowercase letters, in sequence, spelled “Soylent Green is people.”[1]
Detection
The cable easter egg almost always made it through the CIA’s review and distribution system without remark. “It would always make its way through the system. Nobody would pay any attention, until like the one guy is reading it and he’s like, ‘Oh, they did it again.’”[2]
Cultural reference
The hidden line refers to the climactic revelation of Soylent Green, the 1973 American science-fiction film starring Charlton Heston. In the film, set in an overpopulated near-future where most of the public subsists on government-issued nutritional wafers, Heston’s character discovers that the green-colored wafer is manufactured from the bodies of citizens scooped up at protests and at suicide centers. His final, screamed line — “Soylent Green is people!” — is the source quoted by the cable easter egg.[3][1]