Louis Brandeis en un voto singular en un caso de la Corte Suprema de Estados Unidos en 1928:
At one time, Brandeis said, the government “could compel the individual to testify—a compulsion effected, if need be, by torture. It could secure possession of his papers and other articles incident to his private life—a seizure effected, if need be, by breaking and entry.” But, in the twentieth century, he went on, “subtler and more far-reaching means of invading privacy have become available to the Government. Discovery and invention have made it possible for the Government, by means far more effective than stretching upon the rack, to obtain disclosure in court of what is whispered in the closet.”
Más sobre la historia de la vigilancia en el muy documentado artículo de Jill Lepore en el New Yorker.