Quotes of the Day

Julian Assange is about to sit down to explain how his website, WikiLeaks.org, came to publish more than 90,000 secret reports from the war in Afghanistan when he starts to get restless. His chair is made of soft leather, and Assange doesn't like it. "There's no hard surface to slam my fist on and say, 'F______ bastards! I will crash them all!'" he says, smiling.

It's hard to tell whether Assange is joking. A tall, wan, white-haired former computer hacker, Assange is so soft-spoken, it is sometimes difficult to hear him. But just a day earlier, his website released a log of documents that exposed in unprecedented detail the difficulties NATO troops face in Afghanistan.

Nothing gives Assange more pleasure than embarrassing the powerful: he founded WikiLeaks in 2006 as a sort of dead drop for whistle-blowers to anonymously post confidential material. And with six years of the Afghanistan war on display — including many reports of civilian casualties and suspicions that Pakistan's intelligence service and the Taliban are in collusion — Assange has his biggest scoop to date. "I am a journalist, a publisher and an inventor," Assange says. "I have tried to invent a system that solves the problem of censorship of the press and the censorship of the whistle-blower across the whole world."

That's a big claim, but like they say, it ain't bragging if you can do it. In the past few years, WikiLeaks, which consists of six full-time volunteers and about 1,000 part-time encryption experts (the site's main server is in Sweden, though the operation is global), has published a manual from Camp Delta at Guantánamo Bay, an internal report commissioned by oil-trading company Trafigura detailing the dumping of potentially toxic material off the African coast and a video of a 2007 American helicopter attack that killed two Reuters journalists in Baghdad — which Reuters had lobbied unsuccessfully for years to have released. WikiLeaks' release of documents alleging corruption in Kenya won the site an award from Amnesty International. And with the Afghan papers, Assange "has basically guaranteed that think tanks, academics and analysts will study his website for some time. It's history right there on the Internet for everyone to see," says Paul Rogers, a British academic and security correspondent for the website OpenDemocracy.net.

Assange says he is motivated to "protect victims." His website's stated guiding belief is that "transparency in government leads to reduced corruption," and he's happy to take the fight to those governments that he thinks cover things up. Assange says he likes "intellectual combat," and he certainly knows how to throw and dodge a punch. Despite its growing notoriety and prominence, WikiLeaks has only one public spokesman: Assange. The material it posts is not always unfiltered. An abridged version of the 2007 helicopter attack posted on WikiLeaks — which had been edited by Assange and titled "Collateral Murder" — was criticized for failing to show that one of the men fired on by the chopper was carrying a rocket-propelled grenade launcher.

Assange's tactics are part of the reason some open-government campaigners are wary of WikiLeaks even as they remain astonished by its scoops. "It is not journalism. It's data dissemination, and that worries me," says Lucy Dalglish, executive director of the Reporters Committee for Freedom of the Press. "Journalists will go through a period of consultation before publishing sensitive material. WikiLeaks says it does the same thing. But traditional publishers can be held accountable. Aside from Julian Assange, no one knows who these people are."

Assange, an Australian, 39, who studied physics at the University of Melbourne as an adult student, moves between four bases — which he does not specify, citing security concerns. Assange's story is unique to the Internet age. His early career was as a hacker, using the handle Mendax, from the Latin splendide mendax, or "nobly untruthful." In 1991, at age 20, he broke into the master terminal of Nortel, the Canadian telecom company. Assange was caught and pleaded guilty to 26 charges; six other charges were dropped, and he paid only a small fine after the judge commended his "intelligent inquisitiveness."

Assange has retained a hacker's mentality. He works from secret bunkers on major leaks and is convinced he is under surveillance from government intelligence agencies that tail him when he travels. There's a touch of paranoia in his style, but say this for Assange: he takes his work seriously. In discussion with TIME, he offers lengthy and reasoned arguments about U.S. jurisprudence and the importance of the First Amendment.

It's a paradox. While Assange might like to pummel the U.S. for its performance in Afghanistan, he also understands that his work is founded on principles of which the U.S. and its Western allies remain important protectors. "We must make the default assumption that each individual has the right to communicate knowledge to other individuals," Assange says of his decision to publish the Afghanistan papers. "And the U.S. First Amendment is clear that publishers have the right to tell the people what is going on."

• Eben Harrell
• Who's the man behind WikiLeaks, the website that's caused so much trouble? An itinerant Australian hacker