National Security Agency (NSA)

In a new book, Dark Mirror, Barton Gellman writes about his relationship with Edward Snowden and the high-stakes reporting that ultimately garnered him, Poitras and Greenwald a Pulitzer Prize.

NY Times cybersecurity correspondent Nicole Perlroth says hacking tools developed by the NSA were stolen, posted online and are now being used in cyberattacks, including one on the city of Baltimore.

In the book @War, Shane Harris reports that U.S. intelligence agencies, sometimes aided by corporations, are trying to dominate cyberspace. It's "changing the Internet in fundamental ways," he says.

Laura Poitras' new film isn't artfully shaped like her other documentaries. But she captures scenes as history is being made — and it will make you look both ways when you're on the street.

PBS looks at the origins of the agency's surveillance program and the extraordinary steps top government officials took to give it legal cover and keep it hidden.

What motivated the former NSA contractor to divulge careful guarded NSA secrets? A new Vanity Fair article takes a look back at the "kid from the Maryland suburbs."

The NSA managed to penetrate the networks of the giant Chinese telecommunications firm Huawei, documents show. Journalist David Sanger says cyber-espionage is an "entirely new field of conflict."

Before whistle-blower Edward Snowden became a household name, he was an anonymous source. The Washington Post's Barton Gellman recounts how he began corresponding with Snowden and the process of reporting on the government's Internet data mining program.

Shane Harris, an author and journalist who covers intelligence, surveillance and cybersecurity for a number of publications, says that the revelations about the NSA from Edward Snowden are nothing new, and that such programs have a significant recent history in the United States.

Following the attacks of September 11, 2001, the National Security Agency stepped up its efforts to collect intelligence domestically by filtering millions of phone conversations and e-mail messages. In his new book, The Shadow Factory, journalist James Bamford reveals that the ultra-secret agency has half a million people on its watch lists.

In 2005, The New York Times revealed that the National Security Agency had performed wiretaps and other surveillance without court orders. It was a story the Bush administration hoped to keep under wraps, says reporter Eric Lichtblau. Lichtblau's new book is Bush's Law.

In December, New York Times and Eric Lichtblau broke the news that the Bush administration had authorized a domestic eavesdropping program. Risen's new book is State of War: The Secret History of the CIA and the Bush Administration.

James Bamford has investigated the inner-workings of the National Security Agency for his new book, Body of Secrets: Anatomy of the Ultra-Secret National Security Agency: From the Cold War Through the Dawn of a New Century (Doubleday). The book examines the Agency's past and its present activities including the ongoing hunt for the terrorist Osama bin Laden.