Gibson offers me a cup of Yorkshire Gold tea brought over from England. "Glenn got [the story] first, and called me up," she tells me. "But a lot of this is difficult to talk about over open communications. You're like, 'hang on a minute. ... I'm not sure that Skype is a very very good idea.' So we talked in broad terms, and then very quickly got to the next stage where a certain amount of bona fides were being established, and then to: 'Right. I think you just -- get on a plane. Get on a plane.' So he came up here and we talked, and he showed me a very small amount of establishing material, and [we] got very very excited very fast."

Gibson sent Greenwald, along with Ewan McAskill, The Guardian's former diplomatic editor and D.C. bureau chief and a reporter of some 30 years standing, on a plane to Hong Kong to meet Snowden the following morning, at the same time bringing some investigative reporters out to New York from the London office to help process the story. By June 5 they were ready to publish the first story: the FISA order requisitioning Verizon phone data. From Wednesday to Saturday The Guardian published a new scoop each day, and on Sunday June 10 Snowden revealed himself as the whistleblower, explaining his rationale for the leak in a video interview with Greenwald hosted on the Guardian US site.

Greenwald had been working for The Guardian for less than a year, coming from Salon.com in August 2012, but he was already a well-known figure; a trained lawyer, a strident campaigner against the Patriot Act, and an award-winning journalist and author with three books in The New York Times bestseller list. The pedigree, however, does not appear to have impressed The New York Times, which in its coverage of the leak uncharitably referred to The Guardian as a "British news-site" and Greenwald as a "blogger."

In their own way, these labels are fair enough; The Guardian doesn't put out a U.S. print edition, and Greenwald first made his name on his independent blog Unclaimed Territory.But the subtext there was the struggle of the New York Times to encapsulate the hybrid beast that the Guardian has created - which almost certainly helped it scoop the New York Times and other papers -- including The Washington Post -- on the PRISM leak.

During my time in America, I've become convinced that The Guardian is currently unique in the U.S. market. American broadsheet papers write news very differently from their counterparts in the UK; aloof, lengthy, sometimes even a little archaic, The New York Times -- and to a lesser extent The Washington Post and their cohort -- aim to be papers of record, even as they've begun to add daily and weekly blogs to their rosters. The Guardian's style is quite different, with more of an onus on live-blogging, reader engagement, and lighter-hearted content; it can be seen as sitting half-way between The New York Times and online-only outlets like BuzzFeed, despite the fact that its founding actually pre-dates that of The New York Times by thirty years.