Brittany Kaiser is the politics intern who became a pivotal player at Cambridge Analytica, the notorious company accused of handling stolen Facebook data to influence the Trump election and Brexit referendum. The star of Netflix's documentary The Great Hack has now written a book about her decision to go public. Can she be trusted? By Hugo Rifkind.

Brittany Kaiser. You remember. When the British election firm Cambridge Analytica collapsed in disgrace last year, tarnishing Facebook and democracy generally in the process, she was in the middle of it. A whistleblower. Not the first, but certainly the best connected. You may recall the guy with pink hair; you may remember Kaiser's erstwhile boss, Alexander Nix, ashen- faced, dragged into a building by a security guard. Along with them belongs another image, which is that of Kaiser giving evidence to parliament. Blue scarf, strong lipstick, worried face.

More recently you may have seen her in Netflix's The Great Hack, hiding out in Thailand, scared, telling her side of the story. It's complicated, though, from any side. Everybody knows she revealed something important, but hardly anybody seems to understand what it was. Cambridge Analytica has been accused of pillaging the data of Americans to fix the election of Donald Trump, of covert involvement in the Brexit referendum, of facilitating a general assault on western democracy by shadowy billionaires, and of irresponsible and frankly cowboy meddling in the elections of numerous other nations worldwide. Kaiser, herself, has been accused of deploying Israeli computer hackers to skew an election in Nigeria, and of a covert involvement with WikiLeaks. She's still only 33. Now she has come to London to talk about her new memoir, Targeted. It reads like an apology, but it is quite hard to figure out what for.

From the photos and the video I'd expected Kaiser to be small and round, but she is neither. We meet at her publisher's office; she's in cowboy boots and a cowboy hat, even indoors, and a leather jacket, and a necklace that says "Own your data". She lives now, she tells me, mainly in Wyoming. It's calm there. "There are more cows than people," she says. There, she works on blockchain technology, which you don't need to worry about. She also, she says, "hangs out in Congress teaching legislators about technology. Which is fun for me. Although probably not why most people go there."

Alexander Nix, the company CEO, outside Cambridge Analytica's London office, March 2018. Photo / Getty Images

I have a lot more questions. Too many questions, really. I want to know when she found out Cambridge Analytica was handling stolen Facebook data, and whether she was really as shocked about it as she makes out. I want to know whether, when Nix was filmed bragging that his company could entrap politicians by deploying Ukrainian prostitutes, she thinks he meant it. I want to know about Nigeria and the Israeli hackers. I want to know why she met Julian Assange in 2017, and what they talked about, and why she didn't tell parliament about it, even though they asked. I want to know if she was really in fear for her life when she fled to Thailand, and, if so, why she took a film crew. I also want to know who "Chester Freeman" is, because her book mentions him about 100 times, and he's right in the middle of everything, and yet he doesn't, actually, seem to exist. At least, I can find no trace of him.

One way of understanding Kaiser's story is as a sort of political consultancy My Fair Lady. She was a graduate student when she met Nix, and living off student loans. Politically, she was on the left, having interned for Barack Obama's 2008 campaign in her early twenties, and helped to run his first Facebook page. Although American, she'd spent much of her adult life in the UK, first coming to study in Edinburgh at the age of 17.

"Most of my friends," she tells me, "were from the northwest Highlands. They came from families that were fishermen and teachers. I was very happy surrounded by people who had an interesting but very humble upbringing." Then, when she moved to London, her first job was with Amnesty International. "Again," she says, "most people were either not paid very well or were working for free." And lo, she meets Nix, who is already working not only for the Republican Party, but for the most extreme, right-wing bits of it. In her book, she describes him as, "handsome, in a British boarding school sort of way", a man she could easily imagine, she says, "astride a galloping polo pony".

Plunged into his world, her life, too, becomes a whirl of champagne and polo matches and weekends at cottages in the country. He is the mentor; she is the protégée. Without wishing to be creepy about it, she talks about him a bit like Anastasia Steele talks about Christian Grey. Before long, they're bouncing around between London, Davos and Washington DC, meeting global leaders and billionaires. This, pretty much, is the tale of The Great Hack. The modest little liberal girl quite has her head turned.

All this, though, is a little misleading. As she puts it herself, Kaiser's background was not modest. She grew up in Chicago, the elder of two sisters. They both went to private school. Her father, she says, "owned commercial real estate and a string of upscale health clubs and spas" but was hit badly first by the disintegration of Enron, and then by the sub-prime property crash, and finally by illness. "I never thought it would be taken away," she says. "I always thought there would be some kind of padding." In the book, you get the impression that her family are Democrats, and are shocked by her new life. In fact, she tells me, both sides of her family are Republican. "And so it was really weird for the first time to come home for Thanksgiving and Christmas," she says, "and have my family be proud of my political accomplishments. Like, 'Wow, you're working for the company that's working with all of these guys? That's so interesting. Amazing.' "

More to the point, even in London, she was hardly some sheltered church mouse. Between stints of being a student, she had lobbied in Brussels and Geneva and spent time with an NGO in Tripoli. She had spoken at an event with Jack Straw in the House of Lords. When she first met Nix, he was in a Mayfair restaurant with her mysterious friend Freeman, aforementioned, and a pair of politically connected Mongolians. "Both were powerful men I'd met before and liked," she writes of the latter pair. As she left, Nix gave her his card and said, "Let me get you drunk and steal your secrets." What, I ask, does she think he actually made of her? "Note to self," says Kaiser, being Nix. "She has powerful friends."

She first heard the Cambridge pitch from Nix himself, as he bragged to those Mongolians. His company, he told them, held between 2,000 and 5,000 individual data points on every single American, which it could use to microtarget political messaging. They could categorise them, chop them up into groups, send different messages to each one. Later, in a pitch meeting, she heard him outline what those messages would involve, via the example of a cinema that wants to sell more Coke. Most ad agencies, he said, would concentrate on flooding the place with Coke branding. Whereas the Cambridge approach, he said, was to "look at the target audience and ask questions like, 'Under what circumstances would they drink more Coke?' " And then, perhaps, to turn up the heat.

"The simplicity of the concept," she writes, "blew my mind."

Signs for company Cambridge Analytica in the lobby of the building in which they were based on March 21, 2018. Photo / Getty Images

Before long, she was part of the firm. Essentially her job was to sell Cambridge's services to prospective clients, with those clients largely being governments or political parties, and those services, supposedly, being the ability to help them win elections. She would do this by trumpeting past successes, both of Cambridge and of its parent company, the SCL Group, which claimed to have worked on campaigns in nations from South Africa to the Philippines to the Caribbean.

While turning up the heat seems like a pretty malign metaphor to me, Kaiser claims to have, at first, seen only the positives. The work that Nix's group had historically done, she believed, had involved grassroots campaigns, youth movements and voter engagement, reconfiguring any given country's politics to the point that their candidate now answered the questions people were asking. Early on, she says, Nix showed her a photograph of Nelson Mandela, along with the claim that SCL had targeted ANC supporters to help minimise election violence in the country's first democratic elections in 1994. "We worked for a company that was building something important," she writes, "something real that could boost engagement across the connected world."

For all that, her own first project for the firm sounds like absolute chaos. Goodluck Jonathan, the president of Nigeria at the time, was facing what would be a successful challenge from Muhammadu Buhari, a hardliner who had been the country's military dictator. Two months before the election, Kaiser landed a contract to work on behalf of the incumbent. Every bit of this is murky: the client was not Jonathan himself, but "very wealthy Nigerian oil industry billionaires", and she came across them via Prince Idris bin Abdullah al-Senussi of Libya, whom she had apparently met via her Tripoli work. Kaiser, winging it at every step, puts the Nigerians together with Nix, and he pitches them with the Coke thing. They buy it, at a cost of US$1.8 million.

There follows the strangest and at times funniest bit of Kaiser's book, in which the new Nigerian clients turn up to meet her and Nix at Davos, furious, cold and in unsuitable footwear, while she is throwing a party for completely different global billionaires with her friend Freeman. She then takes them trudging through the snow in search of a chicken dinner, while Nix stays behind, hobnobbing with illuminati such as Google's Eric Schmidt. By the time she gets back, the party has descended into something that the Business Insider website will report under the headline, "Davos Party Shut Down after Bartenders Blow Through Enough Booze for Two Nights". Nix then flies home without even seeing the clients, much to their fury. In the end, claims Kaiser, only $800,000 of the money was even spent on the campaign, and the rest was simply kept.

Kaiser would never in fact go to Nigeria. Three years later, a video Cambridge distributed during the election would emerge, in which supposed Buhari supporters attacked people with machetes and a voiceover warned of looming Sharia. To this day, she maintains that she had never seen it before. "People started talking about all this extra stuff," she tells me. "I'd never heard of any of these very dark things happening. All of this brutality and fearmongering. It's not what I saw."

The Observer has also alleged that she herself deployed a firm of Israeli former spies to hack Buhari's emails. Her denial for that one is quite complicated. She had met these shadowy Israelis, she tells me, long before she joined Cambridge Analytica, and they had claimed to be able to do "opposition research" and "investigative work". So, she put them in touch with the client, and they did various things, but which did not involve the alleged hacking, and then came to the Cambridge offices to tell them about it. None of it, she maintains, was useful.

Giving evidence to parliament, Kaiser denied that these Israelis were Black Cube, a notorious Israeli intelligence firm also reportedly employed by Harvey Weinstein to fight abuse allegations. So who, I ask, were they?

"I don't even know the name of the firm," says Kaiser, adding that they always got in touch via encrypted email.

Hang on, I say. But it was you who got in touch with them. You'd met them before. And they came into your office. And you didn't know who they were?

"They had Hispanic names," she says, vaguely. "But there's no way these Israeli guys are called Hispanic names. Right?"

So I ask how she knew they were real and not just con artists, and she says they had brochures. So I ask whether these brochures had any branding on them, and she says, actually, no, as it happens, they did not.

Right, I say, and for a while we both just look at each other.

Sometimes, she's not so careful. In the book, Freeman's friends are only described as "from central Asia", but "Mongolian" slips out often in our chat. Elsewhere, she writes about her thought process before getting involved in the Brexit referendum. At the time, she was dating a Scotsman called Tim. His friends and family, she writes, "were perfectly content to leave the European Union for more self-determination, especially the Scots, who had tried and failed three times to exit the United Kingdom".

As Scotland has only had one independence referendum, I'm not clear what she's talking about, and none the wiser when I ask. "Three times, sure, that's how it happened," she says, a little blankly. "I double-checked."

Kaiser at Burning Man in a scene from The Great Hack. Photo / Supplied

It's not the biggest deal in the world, I know, but it jars, not least from a supposed election expert who once lived in Scotland. Feasibly, she's just read something about the two other devolution referendums, and got it wrong.

Something similar may be behind her aside that the Conservative MP Simon Hart, one of her Digital, Culture, Media and Sport committee (DCMS) interrogators, was "an outdoorsman; when he was not politicking he hunted badgers". Bizarre. He doesn't. It's illegal. Although Wikipedia will tell you that he has campaigned for culling. I mention all this not to nitpick. Rather, it's to note that, when Kaiser occasionally sounds like she doesn't really know what is going on, she is not necessarily just pretending.

Late in 2015, Kaiser appeared on stage next to the Ukip donor Arron Banks at the launch of Leave.EU. This, you'll recall, was the more Ukip-py of the two Leave campaigns, the upstart rival to Dominic Cummings' Vote Leave. The question of whether Leave.EU and Cambridge worked together has long been hotly contested, with both at various times claiming that they did and that they didn't.

The official story now seems to be that Cambridge did preliminary work for Banks, but was never paid for it and had no involvement in the actual campaign. Roughly, this is Kaiser's version of events, too. For a while, she says, Nix and Julian Wheatland (the company's COO) were debating whether to ask Banks and his sidekick Andy Wigmore to stop mentioning them. "Although once Leave actually won," she says, "they let Arron and Andy say whatever they wanted." Only belatedly, she says, once journalists began noticing that no payment to Cambridge had ever been declared to the Electoral Commission (as was a legal requirement), did they realise the risk in this.

Kaiser describes Leave.EU as a ropey operation, to the extent that they once delivered a promised spreadsheet of Ukip members to Cambridge not in an email or on a USB drive, but by sending somebody on a train from Bristol with a large old desktop computer. She still wonders, as do others, whether the eventual campaign was based on her firm's preliminary work, after all.

She also, though, paints a picture of Cambridge avoiding entanglement with official requirements wherever possible. On her last project, in Mexico, she tells me, she and Nix had an argument after she registered with election authorities. "I think he nearly was going to murder me through the phone," she says. "He basically said that was the stupidest decision of my life, and I'd ruined the future of the company in Mexico. But I was, like, that's the law."

From that, I say, she seems to be suggesting that paid election and referendum work could have been done in the UK that, still, nobody knows about.

"It happened all over the world," she says. "That was common practice. So it's very possible that it happened here."

Had Cambridge concentrated only on elections in poorly regulated bits of the third world, which may or may not include Britain, it's perfectly possible the company would still be thriving. Nix, though, had designs on America. By the time Kaiser joined the company, he was already working for Ted Cruz, then gunning for the Republican nomination. As a Democrat, Kaiser was not wild about Cruz. Often, she says, Nix would tell her off for mocking him openly in the office.

Even before Cruz fell by the wayside, the firm was flirting with Donald Trump. Kaiser describes meeting Steve Bannon, who despite being teetotal, looked so bad that she assumed he was hungover. When Nix introduced her as a Democrat, Bannon laughed and called her a spy. Having co-founded Cambridge alongside Nix, Bannon would go on to be Trump's chief strategist in the White House. At the time, though, Kaiser maintains that the entire Trump campaign was widely regarded as ludicrous. The whole idea, she says Nix told her, was a data-gathering forerunner for the launch of Trump TV, intended to be a new conservative media behemoth.

Instead, things got real. Kaiser spent the campaign working alongside Trump's inner team, from Bannon to Kellyanne Conway. Two days before the inauguration, Cambridge would open its new DC office, envisioning a glorious future as the firm that won for Trump.

One day before, she went to a party thrown by Nigel Farage and Arron Banks, at which Farage would sign a copy of Banks' book The Bad Boys of Brexit, thanking her for playing a part. She went on to a Breitbart-sponsored bash called the DeploraBall, at which she wore a National Rifle Association cowboy hat. On the day of the inauguration itself, she would be at a rooftop party hosted by Politico, along with Chester Freeman and his Mongolians, looking down at an audience full of people she now knew, such as Nix, and Bannon, and the billionaire Trump donor (and Cambridge backer) Rebekah Mercer. Barack Obama's Facebook page, I'd imagine, felt a very long way away.

Cambridge was not the only firm that helped Trump, but Kaiser maintains it was the most important. "The only reason Republican operatives try to downplay the role is because they don't want to admit it," she says. "Trump 2020 is staffed by people I hired and trained." The firm's value came in its ability to target US voters using its vast data sets. The trouble was, these data sets were allegedly based on Facebook data they ought not to have had.

To tell a complex story very quickly, some of this data had been harvested via a Facebook questionnaire called "This is Your Digital Life", which collected the data not only of the person playing, but also of all of their contacts. It was then sold to Cambridge. Kaiser already knew that the company had run similar quizzes, including one called "Sex Compass" and another entitled "Musical Walrus". Facebook had changed the rules that allowed such harvesting, and told developers to delete it. Cambridge said they had, but had not.

It was this, in a nutshell, that led to the company's downfall. That story emerged in March 2018 thanks to the pink-haired guy mentioned earlier on, a former Cambridge staffer called Christopher Wylie, and the Observer journalist Carole Cadwalladr. Already the firm was a liberal hate figure, thanks not only to its association with Trump and Brexit, but also to Nix's evident delight in being regarded as a new breed of smooth, election-winning tech Machievelli. There was, I suppose, a fairly broad sense of panic in the air about what these new technologies could make us do, and who had exploited that. And, for a while, even when called before parliament, Nix seemed to bask in being thought of as the key.

Now, though, the smooth shield had cracked. Within days, Facebook was worth US$100 billion less, and the London office of Cambridge would be raided by the UK's data protection watchdog, the Information Commissioner's Office. In many respects, that this technical breach should cause such dramatic fallout was a little bizarre, perhaps even unfair. Plenty of companies were – and indeed, still are – doing very similar things with data that are perfectly legal. Still, Cambridge became the totem of it all. The same week, Channel 4 would publish undercover footage of Nix pitching to a hoax client, offering services such as the entrapment of rival politicians with bribes and Ukrainian prostitutes. "Things don't necessarily need to be true," he said, "as long as they're believed." Whereupon Kaiser decided she wanted out.

Or, at least, that's how she tells it now. Her whistleblowing, though, came the day after The Guardian had published allegations about her own work in Nigeria. It also, at least according to her book, came at the end of a long breakdown in her relationship with Nix. They had fallen out, already, over work for which she felt she was not being properly credited. He was also furious, she says, because she missed an important meeting after losing her passport at the Burning Man festival. Things culminated during a miserable trip to Mexico in which she asked for bodyguards and he said she could pay for them herself.

Had that relationship been stronger, would she still have quit and spoken to the press?

"It's a great question," she says, slowly. "I don't know."

As it was, she flew to San Francisco and spilt the beans to a journalist from The Guardian. Then, with some help from the ever present Freeman, she got on a plane to Thailand. After a couple of days, the makers of The Great Hack joined her. She made sure they turned off geolocation when they filmed, so that nobody could find her. "I know what other whistleblowers have gone through," she says now. "Julian Assange, Chelsea Manning, Edward Snowden ..."

But who were you actually afraid of? Governments? Elements of the American state?

"Or the White House itself," she says. "You've seen the way the president deals with criticism?" Yes, I say. On Twitter. But she doesn't laugh.

As a whistleblower, though, it's hard to believe she's coming completely clean. For one thing, it does seem convenient how little she apparently knew about all the worst things she's now convinced that Cambridge and SCL had done, not only in terms of stolen data, but also with voter suppression and sectarian campaigns in Kenya, Trinidad and Tobago and St Kitts. For another, on some matters, she remains positively cagey. Speaking to the DCMS committee, she answered questions about Nix's alleged attempts to contact Julian Assange for dirt on Hillary Clinton during the US election, but at no point mentioned that she, herself, had visited Assange in the Ecuadorean embassy a few months later.

Then there's the matter of Chester Freeman. He's a huge presence in her book, and indeed in her life, introducing her to Nix, introducing her to clients, taking her to Davos, partying at the presidential inauguration and eventually starting a blockchain company with her. He has pride of place in her acknowledgements. They met, we learn along the way, in Colorado, outside an Obama rally; he's the scion of a billionaire family and a former trade envoy to an island nation which is never named, but is identifiably St Kitts and Nevis. This would make him a fairly prominent person. And yet, Google only knows of one Chester Freeman, and he's a mortgage broker in Oregon.

By odd coincidence, Kaiser is known to be friends with a chap called Chase Ergen. She mentioned him in her DCMS evidence. And in every way, right down to the new blockchain company, he and Freeman appear identical. What's more, she doesn't mention him in her book at all. Are they one and the same?

"No comment," says Kaiser, primly.

Right, I say. But there are only so many former trade envoys to St Kitts in the world. With billionaire parents. From Colorado. With whom you've started a business. I mean, it's not exactly subtle.

"I know," sighs Kaiser, "I know."

Ergen is a fascinating figure in his own right. Earlier this year, he had a starring role in a story reported in Vanity Fair with the headline, "Private Plane Allegedly Carrying Two Billionaires, Jonathan Rhys Meyers and 5,000 Cannabis Plants Grounded in St Kitts", which sort of speaks for itself. His presence in the Cambridge story, though, would be electric.

We contacted Chase Ergen to ask about all this directly, but received no response.

For anyone obsessed with this drama, all this is a story about the intersection of politics and money. Kaiser herself frequently mentions the billionaire Mercer family, who founded the right-wing Breitbart News and helped fund Cambridge itself. Ergen is the son of Charles Ergen, a satellite tycoon ranked by Bloomberg as one of the richest people in the world. In other words, in a story which thrives on shadowy connections with billionaires, she's only gone and added another one.

Whoever Freeman is, I say, might Nix's interest in you have had quite a lot to do with him? "Oh, Alexander made that very clear in the beginning," she says. "He was concentrating on mobilising the Mercer and Bannon networks. 'You have your own network,' he said, 'and you have access to your friend's network, too.' "

Watching Nix speak of smears and bribes and prostitutes, she says, "I wasn't sure if it was something he had actual experience of. Or if he was just bragging to say, you know, I'll do anything to win. Alexander has always been known for overstating everything in order to please the client. So it's hard to know if it really happened. But you know, I feel like I find out new things every week. Nothing shocks me any more."

Writing the book has been like therapy. Until recently, she says, "I was still very defensive. I'd spent quite a few years defending what I had been doing." Now she is learning how it feels to no longer be a pariah.

"I lost a lot of friends when people saw me working with Leave.EU," she says, "and a lot of friends when associating with Ted Cruz and Donald Trump. A lot of those people have not come back. Some have. More Americans than British people. British people are never going to forgive me."

Nix in Cambridge Analytica's New York office, October 2016. Photo / Getty Images

There was even a time, she tells me, when she was shouted at by Matt Damon. It was in Davos. She was introduced as someone from Cambridge Analytica. "And he freaks out," she says. "He just goes, you know, like, 'How dare you?' He's very upset. And Chester pushes him down and says, 'Sit down, Jason Bourne!' And I have never seen a look on his face like that."

"Chester", she calls him, without a flicker. Giggling at the memory, as if he were real. Yet she fails to explain why there's no evidence that he exists.

All of which goes some way to explaining why it is, I think, that I'm not wholly convinced by Brittany Kaiser. I enjoyed her book, but I didn't trust it, and I'd say the same about our conversation. Still, she is unflappable. So much of her story is open to challenge, and I challenged it. Beforehand, I'd expected that we'd have an argument. Instead, she's cheery throughout. More than that, she's positively warm. That's sales for you, I guess.

Today, she is a fervent advocate for data autonomy and even runs an organisation called Own Your Data, as per the necklace. Data, though, is the easy bit of all this. It brought down her company, sure, but it is only the latest tool of an industry that was there before Facebook came, and may even be there after it has gone. Really, this is a story of dark arts and propaganda, however they are delivered. And of the western companies that have deployed them, with cheerful, acquisitive nihilism, in impoverished nations that lack the ability to fight back. Perhaps the hubris of Nix and of his company was to assume they could pull the same trick here. That being said, though, perhaps they could, and perhaps they did.

Book extract

The holy grail of communications is when you can actually start to change behaviour

September 2014

The first time I saw Alexander Nix, it was through the window of a Mayfair sushi restaurant. I had shown up late for a business lunch arranged by my close friend Chester Freeman. I was there to meet with two business associates I knew and one I didn't, all of whom were looking for experts at the intersection of politics and social media. I counted this area as part of my political expertise, having worked on Obama's 2008 campaign, and though I was still busy researching my dissertation for my PhD in London, I was also on the market for a well-paying job.

Chester and the two men I knew were huddled together in the cold outside the restaurant, smoking post-meal cigarettes in view of the neighborhood's Georgian mansions, stately hotels and expensive shops. He rolled me my own and leant in to light it for me. Then he gestured to the plate glass window, through which I glimpsed the third person he'd invited. He appeared to be an average, cut-from-the-cloth business type, mobile phone held tightly to his ear. Chester explained that his name was Alexander Nix and he was the CEO of the SCL Group, short for Strategic Communications Laboratories. He said it was a wildly successful company and explained that its basic function was putting into power presidents and prime ministers and, in many cases, ensuring that they stayed there.

Nix was immaculate and traditional; he was dressed in a dark, bespoke navy suit and a woven silk tie knotted at the neck of a starched button-down – pure Savile Row, right down to his shoes, which had been shined to a blinding polish. He was what I'd call upper-upper crust. He was handsome in a British boarding school sort of way – Eton, as it turned out – and he was trim, with a sharp, arrow-like chin and a slightly bony build. His eyes were a striking, bright blue, and his complexion was smooth and unwrinkled.

Nix greeted me warmly, as if I were an old friend before turning his attention to Chester's other two friends and entering full-pitch mode.

I listened as he laid out the long history of the company. SCL had run more than 200 elections and had carried out projects in some 50 countries worldwide: Afghanistan, Colombia, India, Indonesia, Kenya, Latvia, Libya, Nigeria, Pakistan, the Philippines, Trinidad and Tobago, and more.

"So, we're in America now," Nix was saying, with barely contained enthusiasm.

He was terribly busy, he said, and so hopeful for the future that the SCL Group had had to spin off an entirely new company just to manage the work in the United States alone.

That new company was called Cambridge Analytica – and it was about to cause a revolution.

The revolution Nix had in mind had to do with Big Data. In the digital age, data was "the new oil". Data collection was an "arms race", he said. Cambridge Analytica had amassed an arsenal of data on the American public of unprecedented size and scope, the largest, as far as he knew, anyone had ever assembled. The company's monster databases held between 2,000 and 5,000 individual data points on every individual in the United States over the age of 18. That amounted to some 240 million people.

But it was knowing what to with that data that was the key, he said. And for years, the SCL Group had been identifying and sorting people using the most sophisticated method in behavioural psychology, which gave it the capability of turning information into a gold mine. CA could cause individuals to think, vote and act differently from how they had before and that, he said, is how Cambridge Analytica was going to win elections in America.

October 2014

Chester and I visited the SCL office together. It was tucked away off Green Park, near Shepherd Market, down an alley and off a road called Yarmouth Place, and it occupied a worn-looking building that appeared not to have been rehabbed since the Sixties. It was filled with offices of unknown small start-ups, such as the drinkable-vitamins company SCL shared a hallway with. Wooden crates filled with tiny bottles nearly blocked our way into the ground-floor conference room.

He turned down the lights and pulled up a PowerPoint presentation.

"Our children," he began, clicker in hand, "won't live in a world with 'blanket advertising'."

"The holy grail of communications," he said, "is when you can actually start to change behaviour."

I was only half surprised when Chester called the next morning and said that Alexander had gotten in touch with him and asked if I'd be willing to come back in for a formal interview. I was a 26-year-old American woman who seemed unafraid to have entered high-stakes, high-testosterone arenas.

At the office I was given a brochure which had a section on "psyops", short for "psychological operations", which itself was a euphemism for "psychological warfare".

Shortly after the interview, Alexander called and made me an offer. I could work for the company as a consultant. I could use it as a springboard for fulfilling any number of dreams: becoming a diplomat, an international human rights activist or even a political adviser. But I had no desire to work for the Republicans. Cambridge Analytica had just signed the Ted Cruz campaign and Alexander had made it very clear that he was out to conquer the Republican Party in the United States.

He must have read my mind. He told me my work at the company would only ever be under the SCL Group. No need to work for Cambridge Analytica on the American side, he said. He offered me a part-time consultancy and a decent wage, with the promise of more if I performed well.

"Let's date before we get married, yuh?" he said.

It didn't take long for me to have full-time employment at SCL and enter into the higher echelons of the company.

In an email copying only a handful of people, employees whom Nix considered important and "good fun", he said, he invited us out for lunch one weekend at his home in London. It was in Holland Park, a city house – he had a country one as well – a four-story stone mansion, the interior of which resembled a private members' club or rooms you would find in Buckingham Palace, except that the art that hung from ceiling to floor weren't Old Masters but, instead, provocatively modern. We started at midday with vintage champagne in the drawing room, and continued at the dining table for hours.

I was learning a lot. It seemed to me that my future at the company, if I were to have one, would be in the United States. I told Alexander I wanted to learn the Cambridge Analytica pitch.

I met with Dr Alex Tayler, CA's head data scientist, who taught me about the analytics. We bought data on every American citizen from every vendor we could afford to pay – from Experian to Axiom to Infogroup. We bought data about Americans' finances, where they bought things, how much they paid for them, where they went on vacation, what they read.

We matched this data to their political information (their voting habits, which were accessible publicly) and then matched all that again to their Facebook data (what topics they had "liked"). One day in December 2014, three employees explained to me they had developed a Facebook personality quiz called "the Sex Compass", ostensibly aimed at determining a person's "sexual personality" by asking probing questions about sexual preferences such as favourite position in bed. The survey wasn't just a joyride for the user. It was a new masked way for SCL to gather the users' data and that of all their "friends". There was another test called "the Musical Walrus" to determine that person's "true musical identity". I learnt that when people signed on to play games such as Candy Crush on Facebook, and clicked "yes" to the terms of service for that third-party app, they were opting in to give their data and the data of all their friends, for free, to the app developers and then, inadvertently, to everyone with whom that app developer had decided to share the information.

With all of this, we gave millions of individuals "OCEAN" scores, to determine the construction of their personalities. CA found it was possible to determine the degree to which an individual was "open" (O), "conscientious" (C), "extroverted" (E), "agreeable" (A), or "neurotic" (N). A person's "openness" score indicated whether he or she enjoyed new experiences or was more inclined to rely on and appreciate tradition. The "conscientiousness" score indicated whether a person preferred planning over spontaneity. The "extroversion" score revealed the degree to which one liked to engage with others and be part of a community. "Agreeableness" indicated whether the person put others' needs before their own. And "neuroticism" indicated how likely the person was to be driven by fear when making decisions.

April 2015

In 2015, Facebook announced that as of April 30, it would be closing its user data to "third-party app" developers, companies like CA. After that date, Tayler told me, it would allow data-gathering companies to use the data they had already harvested, and to advertise on its platform and use its analytics, but the companies wouldn't be able to harvest any new data. But other app developers were selling data they had already gathered from Facebook and we could buy it easily from any number of sources.

June 2015

The only thing I knew about Steve Bannon when I met him was that he was the guy who had founded CA with Alexander and the Mercer family. Alexander always spoke about "Steve" with such reverence: He was a power broker, the go-between for CA and Mercer money, the person who made campaigns happen. He was the "godfather of CA".

Steve's house was in the heart of Capitol Hill, a two-story brick Georgian that Alexander called "the Embassy". Alexander had the keys, so we let ourselves in and went down to the basement, where a andful of young people worked quietly at computer stations.

We passed through a set of French doors into a large boardroom and Steve Bannon burst through the doors. Alexander introduced us, making sure to out me as a Democrat.

"So, we've got a spy, do we?" Bannon said, and laughed.

"She's an Obama girl, not a Hillary girl, though," Alexander said, and explained my campaign work in 2008.

"You ran against Hillary, then," Steve said. He pulled out his phone and pulled up a video. "Check this out."

It was a 30 to 40-second advertisement in which an actress dressed as Hillary sat at a desk and, looking over her shoulder, suspiciously exchanged an envelope with someone.

"That's one of our babies," Steve said of the video. He was beaming.

I closed the French doors and made my way around to the computer stations, introducing myself. The people in the room reminded me of my colleagues at Cambridge Analytica – they were young and bright. They identified themselves as reporters, digital designers. Some oversaw the social media. "For Breitbart," they said.

September 2015

Our second trip to see Steve Bannon. He opened the front door wearing a pair of old boxers and a plain white T-shirt. We went over our leads. Among other prospects, Alexander shared that we were about to travel to France to pitch former French president Nicolas Sarkozy. We were also intending to work in Germany, Alexander proudly told Steve – for the party of Angela Merkel, the Christian Democratic Union (CDU).

Steve had opinions about both – he started to tell us that he preferred that we pitch far-right candidates, such as France's National Front politician Marine Le Pen, but the phone buzzed.

He looked at the screen, appeared to be very pleased with himself, and then flipped the phone to face us. The caller ID read, "Donald Trump".

He put the phone to his ear. "Donald!" Steve said, his voice booming. "What can I do for you?" He put Trump on speakerphone. Out came that nasal, arrogant tone I had heard on his reality show.

"I'm going crazy over here preparing for this anti-Iran deal rally," Trump said. He was in New York City. "We're so busy. Everything is getting so big. Very big. When are you going to send me your English guys?!" he shouted.

Steve eyed Alexander and me. "I'm actually here with them right now," he said. "The English guy and Brittany! Shall I send them to you now?"

Extracted from Targeted: My Inside Story of Cambridge Analytica and How Trump and Facebook Broke Democracy

Written by: Hugo Rifkind

© The Times of London