The Watergate scandal was a major political scandal that occurred in the United States in the 1970s as a result of the June 17, 1972, break-in at the Democratic National Committee headquarters at the Watergate office complex in Washington, D.C., and the Nixon administration's attempted cover-up of its involvement. When the conspiracy was discovered and investigated by the U.S. Congress, the Nixon administration's resistance to its probes led to a constitutional crisis. The term Watergate has come to encompass an array of clandestine and often illegal activities undertaken by members of the Nixon administration. Those activities included such "dirty tricks" as bugging the offices of political opponents and people of whom Nixon or his officials were suspicious. Nixon and his close aides ordered harassment of activist groups and political figures, using the Federal Bureau of Investigation, the Central Intelligence Agency, and the Internal Revenue Service.