The King's NSA. : From 1684 to 1984

Monitoring communication, profiling suspicious persons, doxxing one's opponents – long before the arrival of the internet, Europe's kings were already devising sophisticated systems for spying on their subjects. Letters, in particular, were systematically opened and read. A fascinating excursion into the Secret Cipher Chancellery of the Habsburgs, Louis XIV's Black Chamber, and the first era of total surveillance.