10 reasons not to trust claims national security is being threatened by leaks
▻http://www.theguardian.com/uk-news/2013/oct/16/national-security-leaks-gchq-nsa-intelligence-agencies
...in 1984, the Thatcher government banned trade unions at GCHQ describing the move as “essential in order to safeguard national security”. Geoffrey Howe, the foreign secretary, claimed that industrial action a few years earlier had threatened national security, threatened intelligence-gathering during the 1982 Falklands conflict, and could have endangered lives.
None of these claims was true. Asked by the BBC after the ban was imposed how the action had affected national security, Howe replied: “We cannot prove a single example.”
John Nott, the then defence secretary, said after the end of industrial action in 1981 that the dispute with trade unions had not “in any way affected operational capability in any area”. It emerged that GCHQ staff had been praised for their work during the Falklands crisis.