[3] The documentary focuses on Professor David Carroll of Parsons and The New School, Brittany Kaiser (former business development director for Cambridge Analytica), and British investigative journalist Carole Cadwalladr.

In 2015, Cambridge Analytica, a UK-based political consulting firm, began working on behalf of Ted Cruz's campaign to attempt to win the 2016 US Republican nomination.

Independent investigations into data mining, along with whistle-blower accounts of the firm's impact on Brexit, led to a scandal over the influence of social media in political elections.

Further reports followed in the Swiss publication Das Magazin by Hannes Grasseger and Mikael Krogerus (December 2016), (later translated and published by Vice), Carole Cadwalladr in The Guardian (starting in February 2017) and Mattathias Schwartz in The Intercept (March 2017).

[6] When Cambridge Analytica's former CEO Alexander Nix was exposed on Channel 4 as claiming to have 5,000 data points on every American voter, Professor David Carroll took notice.

Cadwalladr's exclusive interviews with Wylie in The Observer reveal how psychographic profiling tactics were carried out with user data scraped from Facebook with the help of Cambridge University professor Aleksandr Kogan.

[11] The filmmakers track down Brittany Kaiser in Thailand, where she considers becoming a whistle-blower and making information about Cambridge Analytica public, or dodging press inquiries and questions.

"[13] Peter Bradshaw writing in The Guardian said the film concerned "the biggest scandal of our time: the gigantic question mark over the legality of the Brexit vote", and awarded it five stars.

[14] Calling the film "a terrifying warning" and "the most important doc this year", Refinery 29 wrote: "The Great Hack makes clear just how deep that shady surveillance can – and does – go.