The Padlock Act was a law enacted in the Province of Québec in 1937 which empowered the Provincial government to close for the duration of a year any building deemed to have been used to promote communism. The name refers to the locks which were placed on the doors of these buildings, condemning them. A flagship aspect of Québec Premier Maurice Duplessis' time in power, the law was used against a number of political groups, as well as against religious minorities, including Jews and Jehovah's Witnesses. It was declared unconstitutional by the Supreme Court of Canada in 1957.