Big Brother and its challengers: Snowden case, encore...

The journalists had been threatened, cajoled and condemned by the British and American governments. Their work together had set off a hunt for their source and a debate on both sides of the Atlantic about government surveillance.

But they had never met — until Friday.

That was when Glenn Greenwald, the journalist, lawyer and civil liberties crusader, and Alan Rusbridger, the editor of The Guardian newspaper, finally shook hands after months of working remotely on articles based on material from the former National Security Agency contractor Edward J. Snowden. The two were in New York for the prestigious Polk Award presented to Mr. Greenwald and his colleagues, Laura Poitras and Ewen MacAskill, and the Washington Post reporter Barton Gellman, for national security reporting.

Mr. Greenwald and Ms. Poitras returned to the United States for the first time since their articles broke in June. They arrived at Kennedy Airport in New York from Berlin, where Mr. Greenwald had given a speech on Thursday and where Ms. Poitras lives and is making a documentary on surveillance.

Mr. Gellman, who revealed the Snowden findings alongside The Guardian, has lived in the United States since their publication beginning last June. But there were fears among Mr. Greenwald’s supporters that he and Ms. Poitras might be detained upon returning to the United States. Federal prosecutors have charged Mr. Snowden with violating the Espionage Act. He has been given asylum in Russia.

The crowd of journalists at the Polk ceremony at the Roosevelt Hotel in Manhattan cheered and applauded when it was announced that Mr. Greenwald and Ms. Poitras had cleared customs and were en route. They arrived just after 1 p.m., trailed by flashing cameras. With the ceremony already underway, Guardian editors, including Mr. Rusbridger, welcomed the two.

“I am finally really happy to see a table full of Guardian editors and journalists, whose role in this story is much more integral than the publicity generally recognizes,” Mr. Greenwald said, as he accepted the award for national security reporting.

It speaks to the increasingly wired and global news-gathering ecosystem that two of the journalists who collaborated on the complex and politically charged revelations from Mr. Snowden about global surveillance had never met. Ms. Poitras, Mr. Greenwald and Ewen MacAskill, a veteran Guardian reporter, flew to Hong Kong to meet with Mr. Snowden, someone they had only known via the Internet until they met in person at a hotel. Mr. Snowden identified himself by carrying a Rubik’s cube.

“New York, Rio, London, Berlin, Hong Kong at one point — it was just a very logistically, ethically complicated story,” Mr. Rusbridger said after the ceremony Friday. His colleagues, including the editor of Guardian U.S., Janine Gibson, her deputy, Stuart Millar, knew Mr. Greenwald well and had hired him to be a columnist the year before.

“It is much more complicated — being dispersed,” Mr. Rusbridger said. “It would have been much easier to all have been in one room — particularly a story of this nature where you assume that every conventional means of communication is suspect in some way.”

On another occasion The Guardian was forced to destroy computer equipment containing material from Mr. Snowden with power tools, under the observation of British government officials.

Despite a trouble-free entry into the United States, Mr. Greenwald and Ms. Poitras had traveled with a lawyer from the American Civil Liberties Union, and a German journalist to document any unpleasant surprises. “The risks of subpoena are very real,” Ms. Poitras said. “We know there is a threat.”

The Guardian and The Washington Post are considered contenders for the Pulitzer Prizes, which will be announced on Monday.

Big Brother and its challengers: Snowden case, encore...

Journalists Who Broke News on N.S.A. Surveillance Return to the U.S.