Review: Be afraid. Be very afraid of big data. The documentary ‘The Great Hack’ tells us why

“The Great Hack� couldn’t be more timely, or unsettling. An intentionally disturbing examination of the Cambridge Analytica scandal, it both explains and offers a warning shot about the misuse of personal data and how that influenced past elections and might well do so in the future.

While the name of that defunct British firm, at one point “the world’s leading data-driven communications company,� is likely familiar, “Great Hack� provides invaluable specifics about what the company did and why it mattered.

Trimmed down as well as featuring additional interviews since it debuted in Sundance, this significant and provocative film is directed by Karim Amer and Jehane Noujaim.

While Noujaim’s last film, the Oscar-nominated “The Square,� showed, among other things, the positive role Facebook had in Egypt’s Tahrir Square uprising, “Great Hack� is nowhere near as optimistic about other aspects of the social media giant.

Because this is a complicated situation, Amer and Noujaim convey its essentials and implications by following the stories of three people of interest.

Introduced first is David Carroll, a professor who teaches digital media at New York’s Parsons School of Design who remembers the initial euphoria over the digital revolution.

“It was the dream of a connected world,� he says, a tool that could function as “our matchmaker, our fact-checker, our entertainer, our therapist.�

But while we were being dazzled by what digital media could do for us, it was taking notes on everything we did, compiling a digital footprint that allowed us to be targeted by advertisers as well as political parties.

“We are the commodity,� Carroll says. “We were so in love, no one read the terms and conditions.�

“Great Hack� follows Carroll (who comes to believe that “data rights are the ultimate human rights�) as he sues Cambridge Analytica in British courts in an attempt to force the firm to reveal exactly what it knows about him.

How this data were acquired by Cambridge Analytica and how the firm came to specialize in using it to manipulate elections is told by two other protagonists, Carole Cadwalladr and the woman who becomes the film’s de facto star, Brittany Kaiser.

Cadwalladr, a veteran reporter for Britain’s Observer newspaper, was key to breaking the story of how Cambridge clandestinely harvested data acquired from Facebook and used it to influence various political campaigns, including the Trump-Clinton presidential race. “Can we,� she asks, “have free and fair elections ever again?�

Kaiser, at one time Cambridge Analytica’s director of business development, has a complicated relationship to data harvesting, as demonstrated by the film’s opening vignette, where she is shown at a recent Burning Man writing the firm’s name on the soon-to-be-incinerated pyre, clearly hoping to expunge it from her life.

Once a true believer who worked at the firm for 3½ years and considered Cambridge’s Chief Executive Alexander Nix a friend and mentor, Kaiser turned into an unlikely whistle-blower who testified to legislative bodies on both sides of the Atlantic.

What Kaiser and other former Cambridge employees revealed is that the company got use of information from a questionable personality test put together by Facebook.

The goal of this test was not to inform users but to harvest personal data from the test-taker as well as the person’s entire friend network about what we like, what we fear, what gets our attention.

This information was used to target what were known as “persuadables� in key states, voters who were, one Analytica employee emphasizes, “bombarded until they saw the world the way we want them to, until they voted for our candidate.�

Something of a loose cannon who is unprepared for the storm that faced her, Kaiser has no answer when a British interrogator says, “it’s a long way from idealistic intern for the Barack Obama campaign to an organization that keeps pretty unsavory company. Didn’t that bother you at all?�

Though no one says so specifically, it feels likely that Kaiser, like many another, was so seduced by being part of the great power that Cambridge Analytica wielded that she was blind to the implications. It’s one of many lessons this involving, up-to-the-minute film insists we consider.