A Senate committee headed by Sen. Frank Church uncovered a train of abuses by intelligence agencies stretching back decades, under presidents of both parties. Employing illegal break-ins, mail-opening programs, concealed bugs, bulk interception of telegrams, and telephone wiretaps, these agencies had gathered information about domestic political dissidents, journalists, labor leaders, and even members of Congress and Supreme Court justices. Perhaps most notoriously, the Church Committee revealed that J. Edgar Hoover had conducted a 10-year campaign to destroy and discredit Martin Luther King Jr., seeking to blackmail him into retirement or suicide with illegal recordings of the civil rights leader’s extramarital liaisons.