Experience should teach us to be most on our guard to protect liberty when
the Government's purposes are beneficent. Men born to freedom are naturally
alert to repel invasion of their liberty by evilminded rulers. The greatest
dangers to liberty lurk in insidious encroachment by men of zeal,
wellmeaning but without understanding.
-- Justice Louis D. Brandeis, dissenting, Olmstead v. United States, 277
-- U.S. 479 (1928)