An attorney with the New Civil Liberties Alliance asked the U.S. Court of Appeals for the Second Circuit on Friday to lift an 18-year-old gag order that barred a former Xerox executive from speaking out about his long-ago prosecution by the U.S. Securities and Exchange Commission, arguing that the enforcement was an unconstitutional prior restraint against free speech.

Lawyers arguing the case of former Xerox Chief Financial Ocer Barry Romeril sought to knock out as unconstitutional a little known but often used tool at the SEC’s disposal in settling civil enforcement cases.

Peggy Little, senior litigation counsel with the NCLA, said that the SEC, which adopted its gag rule in 1972, was only one of two federal agencies that routinely required parties to accept a lifetime gag as a condition of settlements, lest it reopen the case at any time.