NSA chief Keith Alexander tries to win over hackers at cyber fair
Cybersecurity specialists are asked to help make the US government's surveillance programmes better, but many still have privacy concerns

It doesn't get much stranger, even in Las Vegas.
General Keith Alexander, director of the National Security Agency, stood in front of a crowd, selling the idea of US government surveillance programmes.
His audience? More than 3,000 cybersecurity specialists, including some of the world's best hackers, an unruly community that is known for its support of civil liberties and scepticism of the government's three-letter agencies.
Alexander praised the group as one of the brightest collections of technical minds in the world. He asked them to help the NSA fulfil its mission of protecting the country, while also protecting privacy.
"We stand for freedom," Alexander said. "Help us to defend the country and develop a better solution."
But some in the crowd were not buying, and one hacker hurled an expletive back at him. "I'm saying I don't trust you," one shouted.