The Padlock Act (Act Respecting Communistic Propaganda) was a 1937 Quebec statute empowering the attorney general to close, for one year, any building used for propagating "communism or bolshevism" (undefined). A judge could order the lock removed if the owner could prove that the building had not been so used during the preceding year. Further, the Act empowered the attorney general to confiscate and destroy any printed matter propagating communism or bolshevism. Anyone printing, publishing or distributing such material could be imprisoned for up to a year, without appeal. In 1957 the Supreme Court of Canada declared the Act unconstitutional, an invasion of the federal field of criminal law.