When things fall into the wrong hands.

From Bob Woodward and Scott Armstrong's "The Brethren," the 1979 book about the the Supreme Court (in the 1969 Term through the 1975 Term). This vignette takes place after the oral argument in the Watergate tapes case (United States v. Nixon) at page 374:

The clerks turned to humor to kill time as they waited to learn what was going on. One of Powell’s clerks, disturbed by his boss’s memo the day before, drafted a phony opinion and gave it very limited circulation to the clerks’ dining room. “We believe the principle of executive privilege is important…. This case is different from all others that will come before the Court. The Court should be guided by a solicitous concern for the effective discharge of the President’s duties and the dignity of his high office.

“However, we’re deciding this case differently, because Nixon is a crook and somebody ought to throw the son of a bitch in jail.”

Marshall laughed heartily when his clerks showed him a copy. The copies were destroyed for fear that one might fall into the wrong hands.