Gordon Welchman was an Englishman who, while working on decoding German messages at Bletchley Park during World War II, invented traffic analysis. His idea was that even if one couldn’t decipher message contents, just tabulating who messaged whom, when, and how frequently, lent knowledge about the enemy.
After the war, he emigrated to America, where he became an American citizen and taught the first computer course at M.I.T. He worked for Remington Rand and eventually for the MITRE Corporation, where he enhanced traffic analysis technology and helped develop C3 (Command, Control, and Communication) systems.
Following the publication of his book The Hut Six Story in 1982, which detailed the work of his Hut Six group at Bletchley Park, his security clearance was revoked. This killed his career in intelligence.
Today we call the information that surrounds a message “metadata”.