From "Shhhh. U.S. appeals USA PATRIOT loss", by Kevin Poulsen (SecurityFocus, 2005-02-04), regarding the US goverment's secret appeal of a court decision overturning one part of the PATRIOT act:
In one of the documents released last year, the Justice Department even blacked out a quote from a 1972 Supreme Court decision, reading in part: "The danger to political dissent is acute where the Government attempts to act under so vague a concept as the power to protect 'domestic security.'"