What​ matters more: the leaker, or the leak? Any one of the following, you’d think, might have been the news story of the year, or the decade: the revelation that America’s biggest spy agency, the NSA, has information on every phone call made in the continental United States as well as abroad; that it claims to have direct access to the servers of Google, Yahoo, Facebook and all the other major web companies; that GCHQ, the NSA’s British equivalent, is siphoning off the entire internet and storing some of it for thirty days; that online encryption has been subverted and nothing is safe from government spies. The drift of the stories – which were at their peak last summer, when the Guardian and others first got their hands on Edward Snowden’s documents – was that we’re all being watched all the time. Anything we do online, and any phone call we make, is potentially being analysed by the NSA and its friends. But, as Luke Harding discloses in his book on the Snowden affair, the most viewed story in the Guardian’s history wasn’t any of this: it wasn’t a piece of news at all. It was the 12-minute video, made by Laura Poitras and Glenn Greenwald, in which Snowden explained who he was and why he’d decided to reveal what he had.

What was so striking about the video was how calm, articulate and reasonable the leaker seemed. Snowden was interviewed on 6 June last year in a hotel room in Hong Kong. He was wearing a grey shirt and glasses; Poitras filmed him with a hand-held cam. He had already sent Greenwald and Poitras the documents, many thousands of them, on memory sticks: there was no reason for the journalists to be there, though they needed to reassure themselves that he was genuine. But the real reason he’d summoned them from New York was that he didn’t want the substance of the leaks to be overshadowed by the hunt for the leaker: he’d decided to take the unusual step of pre-emptively outing himself as the source. Greenwald said that Snowden had planned to put up a manifesto on the web, calling for an end to the surveillance state, but, Greenwald thought, he came across as a bit ranty and Unabomberish. So he persuaded him not to publish. Snowden’s best strategy was to speak in his own voice to camera: he was his own biggest asset. Here was a man – normal-looking, nice-looking, young – who had given up his $200,000 salary as an NSA contractor and his home in Hawaii (‘paradise’, Snowden called it) in order to let the world know what his government had been doing. As a consequence he faced an uncertain life in exile or, more likely, rendition and indefinite imprisonment: ‘That’s a fear I’ll live under for the rest of my life, however long that happens to be.’ Shortly after his video interview was made public, Snowden disappeared from view. His performance was so impressively unshowy, and he was so quick to step back into the shadows, that the charge that he was a ‘narcissist’ (made, among others, by Jeffrey Toobin at the New Yorker) was hard to make stick.

But his performance had also been so compelling that everyone now wanted a piece of him. In Britain, they wanted a piece of him much more badly than they wanted any aspect of the complicated and ongoing story he’d worked to bring to light. Only the Guardian was publishing substantive material on GCHQ and the NSA. The government had circulated a Defence Advisory Notice, an official request – not enforceable but usually adhered to voluntarily – that ‘further developments’ on the eavesdropping ‘theme’ be avoided, which may have contributed to other outlets ignoring it. But it was also the case that, among UK papers, it was only the Guardian, Greenwald’s then employer, that actually had access to the Snowden documents: there’s little joy in reporting what you don’t have. So nobody was chasing the story, but they were chasing the man, or his ghost: when Snowden left Hong Kong on a flight to Moscow on Sunday, 23 June, the world’s press was in pursuit. Interfax, the Russian news agency, reported that he and a helper – Sarah Harrison, representing WikiLeaks – were booked onto an onward flight to Havana the next day, Aeroflot flight SU150, seats 17a and 17c. As the plane boarded at Sheremetevo Airport on the Monday morning it quickly filled with reporters: CNN’s Phil Black recalled anxiously phoning his bosses to ask whether he should stick with the flight even though there was no sign of his man. The plane was about to take off; journalists searched the loos; a new Twitter account, @SnowdensSeat or ‘17a’, tweeted: ‘I feel empty.’

The much photographed empty seat, a few amusing stories and a thirty-hour round trip were the main rewards of persistence: Snowden, it turned out, had never left Moscow. Nobody knew exactly where he was: somewhere anonymous in the transit zone, or staying invisibly in the capsule hotel? The Telegraph’s Tom Parfitt was dispatched to find him, and spent 43 hours in the airport not succeeding. But it turned out that the global press pack weren’t the only ones confused. Having managed to evade the whole business for three weeks, President Obama was cornered at a press conference on a trip to Senegal on 27 June. ‘I’m sure there will be a made-for-TV movie down the line,’ he said. But ‘no, I’m not going to be scrambling jets to get a 29-year-old hacker.’ Less than a week later, however, scrambling jets turned out to be pretty much the plan. Evo Morales, the Bolivian president, was in Moscow at a conference of natural gas-exporting countries. When asked, he told reporters that Bolivia would in principle consider granting Snowden asylum. This set off alarm bells. Morales left for home from Moscow’s Vnukovo Airport on 2 July, on Bolivian Air Force flight 001 (a second-hand private jet, bought on the cheap off Manchester United). Someone must have suspected that Snowden was on board. The presidential flight was due to fly over Italy, France, Spain and Portugal, refuelling in the Canary Islands. But as it entered Western European airspace it was ordered to turn back. The plane was forced to land in Vienna, where Spanish diplomats asked to be allowed on board. They searched the jet, looking for Snowden in every corner, much as the hacks had done in Moscow. Morales was kept on the ground for 12 hours. Appalled at what Europe had done under American pressure, he complained to the Argentine president, Cristina Kirchner, who relayed his complaint to the world. The irony of the story, as we now know, having seen what happened to Angela Merkel’s phone, is that the NSA would have got hold of the messages between the presidents even before they hit the newspapers.

Why did Snowden matter so much? Mostly because the Americans didn’t know what he still had, and how damaging it could be. For a while the British government appeared to be less concerned. Harding says that, according to conversations with his editors, GCHQ initially seemed to think that ‘thirty to forty’ of their files were in the Guardian’s hands. The government soon realised how wrong that was, and on 18 August David Miranda, Greenwald’s partner, en route from Berlin to Rio, was taken aside at Heathrow and held under Schedule 7 of the Terrorism Act. He was, they believed, carrying an encrypted copy of at least some of the Snowden documents, the estimated number of which has been revised upwards over the months from 50,000 to 200,000 to somewhere approaching two million. All his electronic devices were seized and taken away for analysis. It’s hard to exaggerate how desperate this decision was: Schedule 7 allows a person to be detained on entering the country, and their property searched, if they are suspected of being involved ‘in the commission, preparation or instigation of acts of terrorism’. The trouble for MI5 was that ‘terrorism’ is quite narrowly defined. It involves, for instance, belonging to or inviting support for a ‘proscribed organisation’, or providing ‘instruction or training in the making or use of’ firearms, radioactive materials, explosives, chemical, biological or nuclear weapons. The only weapons Miranda was carrying were digital files; the Guardian wasn’t a proscribed terrorist organisation, nor were any of the other media outlets that Greenwald and Miranda worked with. The other problem for MI5 was that Greenwald is a lawyer, and Miranda’s detention pissed him off.

But all the grounding of presidents and illegal detention of civilians was largely a waste of time: for the British and American security services it was already too late. One of the cleverest things Snowden did, after taking however many thousand documents from the NSA, was to make sure that copies were widely distributed. Only Greenwald and Poitras had the full set. A large number of organisations – the Washington Post, the Guardian, the New York Times, ProPublica, Der Spiegel – had their own copies of many of them. Greenwald, meanwhile, who can also be thanked for many clever decisions, gradually orchestrated a series of carefully chosen and well timed releases of information. They were little bombshells of news, going off around Europe and beyond at regular intervals: the French, Le Monde reported, had had 70 million ‘digital communications’ scooped up by the NSA in a single month; the Spanish, according to El Mundo, had had 60 million phone calls intercepted in a month; Der Spiegel revealed that Merkel’s private phone had been hacked; in Italy, La Repubblica and L’Espresso reported, hidden antennas on the roofs of US facilities were monitoring local transmissions. And so on, from Brazil to India and from Mexico to Russia.

In choosing to give his documents to journalists with mainstream affiliations – Greenwald at the Guardian, Poitras occasionally at Der Spiegel and Barton Gellman mostly at the Washington Post – Snowden had ruled out the early WikiLeaks model of wholescale release of information. (When he first got in touch with reporters, as Harding notes, Snowden used the pseudonym Verax, presumably as a deliberate counterpoint to Julian Assange, who as a young hacker called himself Mendax.) But Greenwald’s brilliance – thanks to his looser than average association with the Guardian, which allowed him to work with and write for whomever he pleased, unlike a normal staff journalist – was to pursue the WikiLeaks strategy of releasing particular material in the places where it would have most impact. WikiLeaks did this very effectively with the US diplomatic cables, finding homes around the globe for nuggets of news that weren’t of much interest to the parochial parts of the Anglosphere. In book publishing terms, it’s a bit like the strategy of the famous Wylie Agency, which pursues the interests of the authors it represents by aggressively fighting their corner in every territory, however small.

But perhaps Greenwald isn’t unlike a terrorist. Those little parcels of news he released were incendiary devices that set off fires and alarms everywhere they landed. Everywhere apart from the UK, where the level of indifference is inexplicably extreme: some blame our love affair with James Bond, others our ineradicable deference to authority figures – though perhaps that’s the same thing. Greenwald’s global hit rate stepped up in the last three months of 2013, after he left the Guardian in October, to join a new media outfit in collaboration with Poitras, Jeremy Scahill and others and funded by the eBay cofounder Pierre Omidyar. (By the time this piece goes to press, the first issue of First Look Media’s first online magazine will be out: it will be something to behold.) One characteristic of targeted incendiary devices, though, is that they don’t have to be very sophisticated or complex to make their effect felt. To know, if you’re French, that 70 million of your ‘digital communications’ – whatever those are – were harvested by the Americans in December 2012 might be enraging, but it is also a piece of information that is effectively no information at all. The great press outcry that hit France in October, though fuelled in part by Hollande’s inability – in stark contrast to Merkel – to say anything rude about the Americans, was essentially derived from a single number on a single PowerPoint slide out of the thousands in Greenwald’s possession. There’s no clue about methods, purpose, systems – or about what went on the month before.

This​ isn’t exactly Greenwald’s fault. The documents weren’t designed to explain everything – and certainly not to outsiders. They have all kinds of functions: there are training brochures, internal marketing materials, reports, emails, slideshows, the lot – everything you’d expect from a vast corporatised bureaucracy. Gleaning actual information from them is at times nearly impossible: sometimes there’s no more than a codename to go on, or a boosterish but vague note about how many ‘events’ the data-gathering machine has managed to capture from a given region. It’s worth remembering that Snowden himself, like everyone else, was only trying to figure a lot of this stuff out. Much of the early reporting made it seem as though he had been an actual user of the arsenal of spying tools his documents disclose – ‘the former intelligence analyst Edward Snowden’ was the BBC’s approved formulation – when in fact, as he made quite clear in his interview from Hong Kong, he was a systems administrator, responsible for maintaining the network for the analysts and others who relied on it. It seems appalling to some that of the estimated 850,000 people in the US with top secret clearance and access to NSA systems, only one man has so far been prepared to leak information on a large scale. But, as he explained, Snowden saw things because of his job that very few others did, including documents that were classified at a level far above top secret. ‘When you’re in positions of privileged access like a systems administrator,’ he said, ‘you’re exposed to a lot more information on a broader scale than the average employee and because of that you see things that may be disturbing. But over the course of a normal person’s career you’d only see one or two of these instances.’

As a non-analyst – as a non-spy – he didn’t necessarily know how all the tools he read about worked. He, like everyone else, was wrong, for instance about the functioning of PRISM, the programme that was the subject of one of the Guardian’s first stories and that seemed so shocking. The slides he saw said that the NSA had ‘direct access’ to the servers of Google, Yahoo, Facebook et al, seeming to imply that Silicon Valley’s richest companies willingly gave the government the keys to all their precious data: this turned out to be an NSA boast, or shorthand, rather than anything much like the truth. But he, like everyone else, was so struck by the outrageousness of the claim that he included the PRISM slides in the first batch of documents he sent Greenwald to whet his appetite. (It later transpired that the NSA was able to access much of these companies’ data in wholesale fashion – without the owners’ knowledge – by secretly tapping the cables that ran between their data centres.) There’s a serious sense in which Snowden is more journalist than whistleblower. That’s not to suggest that what he did is any less valuable: he acted as a journalist of the most impressive kind. He has said that the single document that prompted him to start investigating the way he did – he came across it by accident, while cleaning up the system – was a draft of the NSA inspector general’s 2009 report into George Bush’s warrantless wiretapping programme. The rough scope of that programme became public in 2005 thanks to the reporting of James Risen at the New York Times; the internal report Snowden found – it’s now available unredacted – gave the full story for the first time.

As journalist, Snowden was extraordinarily conscientious. Greenwald says that on the memory sticks he was given the documents were meticulously organised and indexed, with not a single one miscategorised: he didn’t doubt that Snowden had read them all. The evidence certainly points to Snowden’s knowing quite a bit about their contents. In his book Harding describes the moment when Ewen MacAskill, the Guardian journalist who travelled to Hong Kong along with Greenwald and Poitras to meet Snowden for the first time, took out his iPhone and asked Snowden whether he minded ‘if he taped their interview, and perhaps took some photos’. ‘Snowden flung up his arms in alarm,’ Harding writes, ‘as if prodded by an electric stick … The young technician explained that the spy agency was capable of turning a mobile phone into a microphone and tracking device; bringing it into the room was an elementary mistake in operational security, or op-sec.’ Every paranoiac probably supposes as much, but Snowden knew exactly what it was that the spooks might have done to MacAskill’s phone. We too now know, thanks to a document released at the end of January, that GCHQ has developed a virus called WARRIOR PRIDE that can be invisibly installed on devices. It comes with ‘iPhone specific plugins’: the one that does the tracking is TRACKER SMURF; the one that turns the thing into a microphone is NOSEY SMURF. These are facts that you wouldn’t want to unlearn.

The Snowden Files​ – as the iPhone episode suggests – is a super-readable, thrillerish account of the events surrounding the reporting of the documents, with a few interludes sketching out what some of the stories have revealed. If you’re only going to read one of all the books coming out around Snowden – Harding’s is the first of several – then Greenwald’s, due soon, will almost certainly be the one to choose: it’s the most likely to have new information, and a swinging style. But Harding’s is a handy guide to much of what happened. The Guardian’s former Moscow correspondent, Harding was only peripherally involved in reporting the Snowden material: he hasn’t met or spoken to Snowden, though he collaborated on some of the paper’s stories last summer, including one about GCHQ workers’ pub quiz nights and trips to Disneyland in Paris. Despite not having seen much at first hand, Harding has done an amazing – and speedy – job of assembling material from a wide variety of sources and turning it into an exciting account. He has the good storytelling habit of setting a scene in a paragraph or two to draw us into a place. He describes Greenwald’s house in the hills outside Rio, for instance, including its many dogs: ‘The dogs – small ones, big ones, black ones, dun ones – greet visitors by pawing at their legs; dog droppings litter a tropical yard; a mountain stream gurgles alongside.’ I checked out Greenwald’s dog pictures on Facebook: they really are that crazy. He also mentions Greenwald’s modest car, a ‘red Kia (which smells of dog)’. In her December profile of Greenwald in Rolling Stone, Janet Reitman also mentions the ‘somewhat beat-up, doggy-smelling red Kia’, which makes you wonder whether Harding has sniffed it himself – but it hardly matters.

The most exciting parts of the book – perhaps because he was closest to the events they describe – have to do with the drama at the Guardian, particularly as the first Snowden stories were appearing, published out of the paper’s newish office in New York. Harding describes the hectic atmosphere among the journalists in SoHo after they had just pressed publish on the PRISM story and the White House went into panic: ‘Cardboard rectangles of grubby pizza boxes littered the tables; there were takeaway cups and other detritus.’ Into this fervid scene steps Alan Rusbridger, the editor in chief, fresh off the plane from London. Somebody knocks over a cappuccino. This is a gift to Rusbridger, who grabs a newspaper to clear up the mess and says: ‘We are literally wiping the floor with the New York Times.’ It’s a zinger: you do want to root for them.

You also want to root for them, more seriously, when GCHQ sends two representatives to the Guardian’s London office. ‘Ian’ and ‘Chris’, as they refer to themselves, are there to oversee the destruction of the laptops on which the Snowden files were kept. By late July, the government had finally had enough of the stories, and asked that the paper physically destroy the data ‘stolen’ from GCHQ. Rusbridger argued, reasonably, that this was a waste of time and a hopeless attempt to shut the stable door: many other copies of the data existed, in the hands of journalists at several news organisations, and the Guardian itself could carry on its reporting from New York, where the British government had no jurisdiction. But the Cabinet Office insisted anyway. So, under the watchful gaze of Ian and Chris, three members of the Guardian staff attacked a set of laptops with an angle-grinder and a drill; the GCHQ men had also brought with them a degaussing machine, designed to erase any magnetic traces of the data that remained after the computers’ hard drives were smashed up. Harding reports the scene very well, including the air of mutual incomprehension that hung over the encounter. The Guardian people found the GCHQ men alien: they called them the ‘hobbits’. The hobbits were friendly, though, making jokes about black helicopters and describing life in Cheltenham. ‘The hobbits obviously didn’t come down to London often,’ Harding writes. ‘They left carrying bags of shopping: presents for their families.’

In a piece for the New York Review of Books in November, Rusbridger described the destruction of the Guardian data as a hollow victory for the government. It was really a sign of weakness: ‘At some level I suspect our interlocutors realised that the game had changed. The technology that so excites the spooks – that gives them an all-seeing eye into billions of lives – is also technology that is virtually impossible to control or contain.’ I get the sentiment, but I wonder how true this really is: there are, after all, degrees of control. In all the Guardian’s continuing coverage of the Snowden documents – produced in an office on whichever side of the Atlantic – there has, since the summer, been surprisingly little of any great import relating to our own eavesdropping agency: the NSA yes, but there has been nothing on GCHQ even close to the scale of last June’s disclosure of TEMPORA, the cable-tapping project that allows metadata about all intercepted internet traffic entering the UK to be kept for thirty days. It’s perhaps significant that the TEMPORA story was the first the Guardian agreed to make pre-publication changes to at the government’s request; the paper didn’t name the companies that had agreed to the interception (BT, Vodafone etc) until after the names were released by the Süddeutsche Zeitung.

You can still catch news on GCHQ elsewhere, most recently in a piece published by NBC News on 27 January, with Greenwald as one of the contributors. SQUEAKY DOLPHIN is a GCHQ programme that aims to monitor YouTube browsing and Facebook ‘likes’, giving real-time warning of sudden spikes in interest. It’s the sort of analysis, quite handy for spooks, that until now only vast Silicon Valley companies have been able to do: quite a step. So all over the world the leaks keep coming: in fragments, puzzling, hard to decode, the picture never quite clear. You just have to follow them wherever they go.

7 February