Thought Police
The Thought Police (thinkpol in Newspeak) were the secret police of the novel Nineteen Eighty-Four whose job it was to uncover and punish thoughtcrime. The Thought Police used psychology and omnipresent surveillance to find and eliminate members of society who were capable of the mere thought of challenging ruling authority.
Orwell's Thought Police and their pursuit of thoughtcrime was based on the methods used by the totalitarian states and competing ideologies of the 20th century. It also had much to do with Orwell's own "power of facing unpleasant facts", as he called it, and his willingness to criticise prevailing ideas which brought him into conflict with others and their "smelly little orthodoxies". Although Orwell described himself as a democratic socialist, many other socialists (especially those who supported the communist branch of socialism) thought that his criticism of the Soviet Union under Stalin damaged the socialist cause.
The term "Thought Police", by extension, has come to refer to real or perceived enforcement of ideological correctness in any modern or historical contexts.