LONDON (AP/AFP) - Britain's spy chiefs gave public, televised testimony to British lawmakers on Thursday for the first time ever, amid a fierce debate over intelligence tactics following allegations of spying on other governments. Mr Andrew Parker and Mr John Sawers - the heads of Britain's domestic security agency MI5 and its foreign spy service MI6 - appeared along with Iain Lobban, director of the electronic surveillance agency GCHQ, to field questions from Parliament's Intelligence and Security Committee.
Mr Lobban said that revelations from former National Security Agency contractor Edward Snowden led to a change in behaviour on the part of the terrorist groups they monitor. He said that his spies had picked up on "near-daily discussion" of the revelations among his agency's targets. He said they were "discussing the revelations in specific terms of the communications packages which they use, and communications packages they wish to move to". "We have intelligence on (and) we have actually seen chat around specific terrorist groups, including closer to home, discussing how to avoid what they now perceive to be vulnerable communications methods," he added.
"We do not spend our time listening to the telephone calls or reading the e-mails of the majority, of the vast majority. It would not be proportionate, it would not be legal, we do not do it."
Fellow intelligence chief Sawers was more explicit. "The leaks from Snowden have been very damaging, they put our operations at risk. Our adversaries are rubbing their hands with glee," he said. "Al-Qaeda is lapping it up."
Amid continuing revelations about the global scope of United States and British espionage, Mr Parker defended the British intelligence community.
"The suggestion that somehow what we do is somehow compromising freedom and democracy - we believe the opposite to be the case," he said.
The disclosures of the spying, fed by the leaks from former National Security Agency contractor Edward Snowden, have sparked a global debate over privacy and surveillance and are likely to feature heavily in the spy chiefs' testimony.
Mr Parker has previously described the leaks as a "gift" to terrorists.
Committee chairman Malcolm Rifkind said the trio will be questioned on the work of their agencies, their current priorities and threats to Britain, but not on ongoing operations.
The committee previously has taken testimony in private from the security chiefs. Thursday's appearance was being televised with a slight delay.