Luke Harding - The Snowden Files

Snowden was one of around 1,000 NSA ‘sysadmins’ allowed to look at many parts of this system. (Other users with top-secret clearance weren’t allowed to see all classified files.) He could open a file without leaving an electronic trace. He was, in the words of one intelligence source, a ‘ghost user’, able to haunt the agency’s hallowed places. He may also have used his administrator status to persuade others to entrust their login details to him. GCHQ trustingly shares its top-secret British material with the NSA, which in turn makes it available to an army of outside contractors. This meant Snowden had access to British secrets, too, through GCHQ’s parallel intranet, GCWiki.

Although we don’t know exactly how he harvested the material, it appears Snowden downloaded NSA documents onto thumbnail drives. The method is the same as that used by Manning, who downloaded and sent to WikiLeaks a quarter of a million US diplomatic cables on a CD marked ‘Lady Gaga’ while working in a steamy field station outside Baghdad.

Thumb drives are forbidden to most staff. But a ‘sysadmin’ could argue that he or she was repairing a corrupted user profile, and needed a backup. The thumb drive could then be carried away to bridge the ‘airgap’ that existed between the NSA system and the regular internet.

Why did nobody raise the alarm? Was the NSA asleep? Sitting in Hawaii, Snowden could remotely reach into the NSA’s servers, some 5,000 miles away in Fort Meade, through what was known as a ‘thin client’ system. Most staff had already gone home for the night when Snowden logged on, six time zones away. His activities took place while the NSA napped. Plus Snowden was extremely good at what he did – he was an ‘IT genius’ in the words of Anderson, his friend from Geneva – so he was able to move undetected through a vast internal system.

After four weeks in his new job, Snowden tells his bosses at Booz he is feeling unwell. He wants some time off and requests unpaid leave. When they check back with him he tells them he has epilepsy. It is the same condition that affects his mother Wendy, who uses a guide dog.

And then, on 20 May, he vanishes.

Mills’s blog reflects some of the pain and anguish she felt on discovering that E had walked out of her life. By 2 June it becomes clear something has gone very wrong.

She writes: ‘While I have been patiently asking the universe for a livelier schedule I’m not sure I meant for it to dump half a year’s worth of experience in my lap in two weeks’ time. We’re talking biblical stuff – floods, deceit, loss… I feel alone, lost, overwhelmed, and desperate for a reprieve from the bipolar nature of my current situation.’

Five days later Mills removes her blog. She also wonders publicly about deleting her Twitter account. A creative body of work stretching back over several years, it includes dozens of photos of herself, and some of her E.

‘To delete or not to delete?’ she tweets. She doesn’t delete.

‘Whoso would be a man must be a nonconformist.’

From the top of Sugar Loaf Mountain, the city of Rio de Janeiro appears as a precipitous swirl of greens and browns. In the sky, black vultures turn in slow spirals. Below – far below – is downtown and a shimmer of skyscrapers. Fringing it are beaches and breakers frothing endlessly on a turquoise sea. Standing above, arms outstretched, is the art deco statue of Christ the Redeemer.

Rio’s famous beaches, Copacabana and Ipanema, lie at either side of a claw-shaped stretch of coast. Copacabana has long enjoyed a louche reputation. And yes, there are lewd sand sculptures of skimpily dressed women with big buttocks, next to green-yellow-blue-white Brazilian flags. But these days Copacabana is more of a hangout for the geriatric rich. Few others can afford to live in the luxury flats overlooking this dreamy Atlantic coast.

On weekday mornings, residents emerge, stretch, and walk their pampered pooches. Skateboarders trundle along a cycle lane; there are juice bars, restaurants, pavement cafes. Over on the beach tanned locals play football – Brazil’s national obsession – or volleyball. Much of human life is here, sitting in the balmy days of winter under the rubber trees. But the girl from Ipanema is a rare sight. You are more likely to encounter her granny.

From Rio’s south-western district of Gávea, the road twists sharply up into Floresta da Tijuca, the world’s biggest urban forest, home to capuchin monkeys and toucans. It’s usually several degrees cooler than the sea-level beaches. Keep going and you eventually arrive at a secluded mountain home. Is it some sort of dog sanctuary? A sign on the metal gate proclaims ‘Cuidado Com O Cão’: beware of the dog. The warning is superfluous: from the house comes a wild yapping and yowling. 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. If there is mutt heaven, this is surely it.

The house’s non-dog denizen is Glenn Greenwald. Greenwald, aged 46, is one of the more prominent US political commentators of his generation. Well before the Snowden story made him a household name, Greenwald had built up a following. A litigator by profession, he spent a decade working in the federal and state court system. The son of Jewish parents, truculent, gay, radical and passionate about civil liberties, Greenwald found his voice in the Bush era. In 2005 he gave up his practice to concentrate on writing full time. His online blog attracted a wide readership. From 2007 he contributed to Salon.com as a columnist.

From his home in Rio, Greenwald frequently appears as a pundit on US TV networks. This means driving down the mountain in his red Kia (which smells of dog) to a studio in the city’s hippodrome. Security staff greet him warmly in Portuguese – he speaks it fluently. The studio has a camera, a chair and a desk. Seated at the desk, the camera depicts him in the uniform of a killer lawyer: clean shirt, smart jacket, tie. Under the table, and unseen by his audience in New York or Seattle, Greenwald will wear flip-flops and a pair of beach shorts.

This hybrid outfit bespeaks a wider duality, between private and professional. In his private life, Greenwald is soft-hearted. He is obviously a sucker for distressed beasts; he and his partner David Miranda have scooped up 10 strays. They also dog-sit other people’s and keep an additional cat. Greenwald and Miranda met when the journalist came to Rio for a two-month holiday in 2005; it was Greenwald’s second day in town, and he was lying on the beach. They quickly fell in love; Greenwald says he lives in Miranda’s Brazilian coastal home city because US federal law refused to recognise same-sex marriages. (It does now). Miranda works as Greenwald’s journalist-assistant. And when you meet him, Greenwald is mild, easy to get along with, chatty and kind.

Professionally, though, Greenwald is a different creature: adversarial, remorseless, sardonic and forensic. He is a relentless pricker of what he regards as official US hypocrisy. Greenwald has been a waspish critic of the George W Bush administration, and of Obama. He is scathing of Washington’s record. Citizens’ rights, drone strikes, foreign wars, the US’s disastrous engagement with the Muslim world, Guantanamo Bay, America’s ‘global torture regime’ – all have been subjects for Greenwald’s Swiftian pen. In long, sometimes torrential posts, he has chronicled the US government’s alleged crimes around the world. Greenwald’s outspoken views on privacy make him arguably America’s best-known critic of government surveillance.