NSA chief defends Prism programme in hacker speech THE head of the US National Security Administration, General Keith Alexander, has defended the American government's collection of phone and internet records to a conference of hackers in Las Vegas. Gen Alexander told the Black Hat conference yesterday the ability to look for patterns in telephone and e-mail communications has stopped terror attacks in the US and other countries. The far-reaching activities of the NSA were exposed by former government contractor Edward Snowden, who is now a fugitive from US justice. Mr Snowden's release of the surveillance information to American and European media sparked an uproar over revelations that US intelligence agencies collected data on phone calls and other communications Yesterday marked the first time since Mr Snowden's revelations that Gen Alexander has spoken publicly to security researchers who explore vulnerabilities in networks and let companies or agencies know they exist. However, about 30 minutes into his presentation at the annual conference, Gen Alexander was interrupted when a 30-year-old security consultant named Jon McCoy shouted "Freedom!" "Exactly," responded Gen Alexander. We stand for freedom. Bullshit! Mr McCoy shouted. "Not bad," Gen Alexander said, as applause broke out in the crowd. But I think what you're saying is that, in these cases, what's the distinction? Where's the discussion and what tools do we have to stop this? "No, I'm saying I don't trust you!" shouted Mr McCoy. You lied to Congress. Why would people believe you're not lying to us right now?" another voice in the crowd shouted. "I haven't lied to Congress," Gen Alexander said. I do think it's important for us to have this discussion. Because, in my opinion, what you believe is what's written in the press without looking at the facts. Information collected under the Prism programme - the NSA's controversial intelligence gathering system - along with another programme that collects phone data from millions of Americans, has been crucial to thwarting 54 terrorist plots, 13 of which were in the US, Gen Alexander told the conference. For example, an intercepted e-mail from a terrorist in Pakistan led to the interruption of the New York subway bombing plot in 2009, he said. "It would have been the biggest terrorist attack since 9/11 on US soil," he added. Meanwhile, the US director of national intelligence yesterday released three declassified documents that authorised and explained the bulk collection of phone data, one of the secret surveillance programmes revealed by Mr Snowden. The documents released include 2009 and 2011 reports on the NSA's "bulk collection programme," carried out under the US Patriot Act. In addition, they include an April 2013 order from the Foreign Intelligence Surveillance Court, which directed communications company Verizon to hand over data from millions of Americans" telephone calls and described how that data should be stored and accessed. Much of what is contained in the documents has already been divulged in public hearings.