The academic at the centre of the Cambridge Analytica scandal is suing Facebook for defamation over the social network’s claims that he lied about why he was harvesting personal data from profiles on the site.

Aleksandr Kogan, a former psychology researcher at the University of Cambridge, was the developer of a personality quiz app that paired individual psychological profiles with personal data scraped from the Facebook pages of quiz-takers and their online friends. That data was used as the root of Cambridge Analytica’s “psychometric” approach to targeting users with political adverts tailored to their personalities.

Facebook has always claimed that it was misled by Kogan about how the data was used, and suspended his access to the platform in the wake of the Observer breaking the news about Cambridge Analytica’s data-harvesting operation.

The social network said that its rules banned such a reuse of data – but Kogan has always argued that the terms and conditions of his own app explicitly said the results would be used for more than just academic purposes.

The Cambridge Analytica scandal changed the world – but it didn't change Facebook Read more

Now, Kogan has sued, arguing that Facebook’s repeated attempts to pin the blame for the scandal on him are defamatory.

“Alex did not lie, Alex was not a fraud, Alex did not deceive them, this was not a scam,” Steve Cohen, Kogan’s lawyer, told the New York Times, which first reported the lawsuit. “Facebook knew exactly what this app was doing, or should have known. Facebook desperately needed a scapegoat, and Alex was their scapegoat.”

In a statement, a spokesperson for Facebook said Kogan’s case was a “a frivolous lawsuit from someone who recklessly violated our policies and put people’s data at risk”.

Almost since the scandal broke, Kogan has argued that he was a scapegoat in a war between larger players. “I’m being basically used as a scapegoat by both Facebook and Cambridge Analytica,” he said in March 2018, the week after the news broke. “Honestly we thought we were acting perfectly appropriately. We thought we were doing something that was really normal.”

The following month, Kogan appeared in front of British MPs, and said: “I think [Facebook] realise that their platform has been mined left and right by thousands of others and I was just the unlucky person that ended up somehow linked to the Trump campaign, and we are where we are.

“I think they realise all this, but PR is PR and they’re trying to manage the crisis, and it’s convenient to point the finger at a single entity and try to paint the picture this is a rogue agent.”

Steve Cohen, Kogan’s lawyer, told the Guardian: “Facebook knew, or should have known that what they said about Dr Kogan was not true. He didn’t lie to them and his work was not a ‘scam’.

“In fact, Facebook had collaborated on several academic papers about his work, and Dr Kogan told Facebook that the new version of the app would be used for commercial purposes. Just as he informed potential users. But facing growing criticism about its policies, Facebook went into PR overdrive and found a convenient scapegoat in Dr Kogan. They defamed him and we look forward to a jury deciding the proper remedy.”