In 1985, Massiter, who as an MI5 officer had been responsible for the surveillance of CND from 1981 to 1983, resigned and made disclosures to a Channel 4 20/20 Vision programme, "MI5's Official Secrets". 8 March 1985 - Former MI5 Officer Cathy Massiter expresses disquiet about MI5's over zealous definition of term "subversive" in Channel 4's 20/20 Vision programme "MI5's Official Secrets".
Ms Massiter reveals the National Council for Civil Liberties and CND are classified as 'subversive'.
She claims MI5's definition of subversion was being distorted and widened, saying: "We were violating our own rules. It seemed to be getting out of control."