Facebook has suspended data analysis and marketing firm Cambridge Analytica following claims that it breached an agreement with the social-media website when it used an ostensibly academic app to harvest data on 50 million users.
It follows revelations over the weekend by whistleblower Chris Wylie, a former contractor at Cambridge Analytica who went on to found his own, similar company.
Those claims were published in The Observer and The New York Times. The newspapers claim that Cambridge Analytica obtained the Facebook data via an app built by Cambridge University academic Aleksandr Kogan.
Through his company Global Science Research, in collaboration with Cambridge Analytica, Kogan built an app called 'thisisyourdigitallife' that paid hundreds of thousands of Facebook users to take a personality test and agree to have their data collected for academic use.
The app, however, also collected the information of the test-takers' Facebook friends, something allowed by Facebook until 2015, which lead to the accumulation of a data pool "tens of millions-strong".
Kogan, who worked with Wylie to obtain the data, then sold the information to Cambridge Analytica, according to The Observer, a move that went against Facebook's 'platform policy' that only allowed for the collection of friends' data to improve the user experience.
"We exploited Facebook to harvest millions of people's profiles. And built models to exploit what we knew about them and target their inner demons. That was the basis the entire company was built on," Wylie, former research director at Cambridge Analytica, said.
This data was then turned into information used by the likes of Steve Bannon and the Donald Trump Campaign to "micro-target" individuals based on shared characteristics.
The Observer describes this as one of Facebook's "biggest ever data breaches" with the stolen information used "to build a powerful software program to predict and influence choices at the ballot box".
Documents seen by the newspaper show that Facebook knew about the "unprecedented" data harvesting by late-2015, but failed to alert users and took only "limited steps" to recover and secure the private information.
In response to the revelations, Facebook announced that it was suspending Cambridge Analytica and Kogan from the platform, pending further information over misuse of data.
Cambridge Analytica has denied any wrongdoing and says that its parent company Strategic Communication Laboratories [SCL] hired Kogan to undertake "a large-scale research project in the US", none of which was used in the firm's 2016 election work.
Facebook said in a statement that "the claim that this is a data breach is completely false". It added: "Aleksandr Kogan requested and gained access to information from users who chose to sign up to his app, and everyone involved gave their consent.
"People knowingly provided their information, no systems were infiltrated, and no passwords or sensitive pieces of information were stolen or hacked."
That isn't going to stop the firm from facing investigations, though, with both the Electoral Commission and Information Commissioner's Office announcing on Saturday that they would be looking into whether Facebook data had been "illegally acquired and used".
Information Commissioner Elizabeth Denham said: "We are investigating the circumstances in which Facebook data may have been illegally acquired and used.
"It's part of our ongoing investigation into the use of data analytics for political purposes which was launched to consider how political parties and campaigns, data analytics companies and social media platforms in the UK are using and analysing people's personal information to micro-target voters."
In the US, Massachusetts attorney general Maura Healey also announced her office is opening an investigation into the social networking site.
BT wants to make the public switched telephone network history within eight years
Personal data being purloined by third parties via Facebook Login API
MacOS and iOS are better off apart, says CEO Tim Cook
Or they'll no longer be entitled to updates and bug patches