The Prime Minister said that the surveillance activities of GCHQ and its American counterpart, the NSA, disclosed by the former US intelligence operative Edward Snowden, were all aimed at protecting the public.
“We have very good rules in this country. If a telephone call is going to be listened in to, that has to be signed off by the Home Secretary personally. There are very good safeguards in place,” told ITV’s The Agenda.
“You get asked, ‘What are the rules’? I’m satisfied we have pretty strong safeguards. I thought part of the reaction to the The Guardian story was - big surprise, spies learn to spy...it’s to help keep us safe.”
Mr Cameron disclosed that he had seen part of the new film about WikiLeaks founder Julian Assange - Fifth Estate, starring Benedict Cumberbatch.
While the Prime Minister said he had some sympathy for some of the early WikiLeaks disclosures, later mass releases of documents by the whistle-blowing website had put lives at risk.
“You do feel sympathy for them. Some of the things they uncover...it’s great some of that information has been revealed. Transparency...helps keeps governments and politicians honest,” he said
“Later on (in) the film there are just huge dumps of information made public without thinking of consequences, of whose lives could be put at risk. There are some things the Government has to keep secret for national security, for people’s safety. That has to be part of the debate too.”
Mr Cameron also admitted that he worried about the consequences of exposing his wife, Samantha, and their children to media scrutiny.
“It’s an issue of judgment. There is the option - some politicians say ‘right, my family life will be entirely private’. If that’s your decision that’s absolutely fine,” he said.
“I think people want to know a bit about you and what makes you tick and I have talked about my family and Samantha and I do things together but you know as soon as you do that you’re opening them up to greater scrutiny.
“The scrutiny has got to be fair. I had an episode where the Mirror went through my dustbins to prove I wasn’t a ‘good green dad’ because I wasn’t using recyclable nappies. To me I just think that’s totally over the top, going through dustbins.”
He backed Labour leader Ed Miliband in his battle with the Daily Mail over an article which it ran attacking his late father, the Marxist intellectual Ralph Miliband, under the headline “The Man Who Hated Britain”.
“If it was my dad I’d be out in print defending him as strongly as I could,” he said. “What was wrong was the headline, he clearly didn’t hate Britain. Ed was right to come out.”