Every regime has its watchers. This course follows secret policing from the Okhrana and Gestapo to the KGB, Stasi, Iran's Ministry of Intelligence and Security, Israel's Shin Bet, and Cuba's DGI, exploring recruitment, informant networks, surveillance technology, detention, and the societal terror of disappearances. We compare authoritarian models with democratic oversight and close with the archive-opening and transitional justice efforts that have forced these shadow states into the light. Who watches the watchers?