The man who claimed to leak state secrets on U.S. government eavesdropping sought to break the story through a columnist for a U.K.-based publication who has made no secret of his distaste for intrusions on privacy.

Edward Snowden brought his information to Glenn Greenwald of The Guardian instead of to the Washington Post, with which he had briefly corresponded. The case illustrates the passion an opinion-driven journalist can bring to a breaking news story; at the same time it raises questions about fairness.

Mr. Greenwald, author of three books in which he argues the government has trampled on personal rights in the name of protecting national security, wrote the original stories exposing the extent of the government’s data collection. Over the weekend, he identified intelligence contractor Snowden as his source at the latter’s request, and said more stories are coming.

“What we disclosed was of great public interest, of great importance in a democracy, that the U.S. government is building this massive spying apparatus aimed at its own population,” Mr. Greenwald said on Monday on MSNBC’s “Morning Joe.”

Mr. Greenwald also told The Associated Press that he’s been contacted by “countless people” over the last 24 hours offering to create legal defence funds for Mr. Snowden.

The topic is personal for Mr. Greenwald (46). The former constitutional and civil rights lawyer, educated at the New York University Law School, began the “Unclaimed Territory” blog in 2005 and wrote “How Would a Patriot Act?” a year later. The book criticized the Bush administration for its use of executive power.

Mr. Greenwald, now based in Brazil, wrote a regular column for Salon for five years until joining The Guardian last year.

Elaborating on the surveillance programme, he wrote, one programme collects hundreds of millions of U.S. phone records. The second programme takes in audio, email and other electronic activities primarily by non-U.S. nationals who use providers such as Microsoft and Apple. Mr. Greenwald described the collection of phone records on Monday as “rampant abuse and it needs sunlight. That’s why this person came forward and that’s why we published our stories.

On “Morning Joe,” he snapped that co-host Mika Brzezinski was using “Obama talking points” when she challenged him with a question.

“The wall of secrecy behind which they operate is impenetrable and it is a real menace to democracy,” said Mr. Greenwald, who won a 2010 Online Journalism Association award for his coverage of Bradley Manning, who is charged with giving classified documents to WikiLeaks.

Mr. Snowden, however, had not just gone to Mr. Greenwald with his information. Barton Gellman of The Washington Post wrote on Sunday that Mr. Snowden had contacted him about the story. He said Mr. Snowden had asked that the Post to publish within 72 hours the full contents of a presentation he had made about the collection of electronic activity from the Silicon Valley companies.

Mr. Gellman said the Post would not make any guarantees and sought the government’s views about whether the information would harm national security. The Post eventually agreed to publish a small sample of what Mr. Snowden was offering, but Mr. Snowden backed away, writing that “I regret that we weren’t able to keep this project unilateral,” Mr. Gellman wrote.

Mr. Greenwald’s clear point of view doesn’t necessarily weaken the story, said Jay Rosen, journalism professor at New York University and author of the Press Think blog.

“In many ways it strengthens it,” he said. Mr. Greenwald has a clear stance on privacy and national security, but they aren’t partisan; he’s criticized Democratic President Barack Obama and his Republican predecessor, George W. Bush. Journalists with strong viewpoints, is a tradition with a long history in the U.S., Mr. Rosen said.

“The fact that sources now may choose (outlets) on the basis of commitment is a fact and journalists whose professional stance is no commitment may find themselves at a disadvantage,” he said.

Mr. Greenwald’s known feelings on the issue “does leave a little opening for critics,” said Ellen Shearer, head of the national security journalism initiative at Northwestern University. There’s always a risk that such passion can work against a journalist; some people would worry that facts contradictory to a predisposed belief could be overlooked.

To this point, Mr. Shearer said there’s been little pushback on the facts, with the debate primarily about whether the information should be published.

Intelligence officials are investigating the leak and its impact on its programs. Director of National Intelligence James Clapper called the revelation of the intelligence-gathering programmes reckless and said it has done “huge, grave damage.”

The Guardian took care not to publish material that may help other countries improve their eavesdropping or could put the lives of covert agents at risk, Mr. Greenwald said.

“We’ve published these things they marked ‘top secret’ that don’t actually harm national security but conceal what they’ve done from the public,” he said.

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