Spymasters turn their fire on whistleblower

MI6 chief Sir John Sawers said al-Qaida were “rubbing their hands with glee” at the exposure of the surveillance methods used by monitors at GCHQ and its US counterpart, the National Security Agency.

Sir Iain Lobban, the director of GCHQ, told MPs that in the five months since Mr Snowden’s revelations started appearing, they had monitored terrorist groups discussing in “specific terms” how to avoid communications systems they now considered vulnerable.

They were beside MI5 director-general Andrew Parker in an unprecedented first public appearance by the heads of the three agencies before the parliamentary Intelligence and Security Committee.

In a dramatic 90-minute hearing at Westminster, they made plain their anger at the damage they said had been done to national security as a result of the leaks and insisted they operated at all times within the framework of the law and did not engage in mass “snooping” against ordinary citizens.

Sir Iain suggested they could help serious criminals and even paedophiles avoid detection as the success of surveillance operations depended upon the targets being “unaware or uncertain” of the methods being used against them.

When those methods were made public, the effect, he said, could be a “sudden darkening” of the intelligence picture.

“More often it is gradual, but it is inexorable. What we have seen over the last five months is near daily discussion amongst some of our targets,” he said.

“We’ve seen terrorist groups in the Middle East, in Afghanistan and elsewhere in south Asia discussing the revelations in specific terms, in terms of the communications packages that they use, the communications packages that they wish to move to.

“We have actually seen chat around specific groups, including closer to home, discussing how to avoid what they now perceive to be vulnerable communications methods, or how to select communications which they now perceive not to be exploitable.”

Sir John said the leaks had been “very damaging”, risking operations and making recruitment more difficult.