Cambridge Analyica, which has now been suspended from Facebook, stands accused of fraudulently obtaining Facebook user data and then using it to run election ads on U.S. president Donald Trump's behalf.
Facebook has suspended the account of a company that ran data for President Donald Trump's campaign.
The Canadian whistleblower at the centre of an worldwide scandal that saw a firm help the Trump campaign capitalize politically from private Facebook information got his start in politics with the Liberal Party of Canada.
The scrutiny presented a new threat to Facebook's reputation, which was already under attack over Russians' alleged use of Facebook tools to sway American voters before and after the 2016 USA elections.
"Facebook has been on trial in the past 12 months in the court of public opinion", said Stephen Hahn-Griffiths, chief research officer at the Reputation Institute, which assesses public attitudes.
Facebook said on Sunday it was conducting a "comprehensive internal and external review" to determine if the personal data of 50 million users that was reported to be misused by a political consultant still existed.
The reports say Cambridge Analytica also played a major role in the referendum that led to Britain's vote to leave the European Union.
"They say 'trust us.' Mark Zuckerberg needs to testify before Senate Judiciary", she added, referring to Facebook's CEO and a committee she sits on.
Facebook said it found out about Cambridge Analytica's access in 2015, after which it had the firm certify that it deleted the data.
"This was unequivocally not a data breach, " longtime Facebook executive Andrew Bosworth said on Twitter.
Despite assurances at the time this was discovered in 2015 that the data had been destroyed, Facebook has since been informed this did not happen, prompting the suspension of the firm on suspicion it flouted privacy rules. CNN points out that Chancellor and Kogan were both listed as directors when GSR incorporated in May 2014, according to United Kingdom government records, but Cambridge Analytica claims "no recollection" of any emails or calls with Chancellor.
Facebook acted as The New York Times and The Observer of London exposed Cambridge Analytica's acquisition of the data, calling it a "breach" that "underpinned" the analytics firm's "work on President Trump's campaign in 2016".
The social network said in a blog post that the firm violated its policies by receiving user data from a Facebook app created by a University of Cambridge professor.
Up to 270,000 people downloaded the app, allowing the data research company to access the relevant data from the profile such as the city a user lives in, or the content they had liked.
"Data has been taken from Facebook users without their consent, and was then processed by a third party and used to support their campaigns", Mr Collins wrote on the House of Commons website.
The latest incident has raised new questions about what technical guardrails Facebook has in place to prevent authorised users from sharing sensitive information, and how much visibility the company has into how outsiders use the data.
Each new issue has also raised the same enduring questions about Facebook's conflicting priorities - to protect its users, but also to ensure that it can exploit their personal details to fuel its hugely lucrative, and precisely targeted, advertising business.
Discussion of services offered by Cambridge Analytica was apparently going right to the top of Lukoil, even though its retail operations in America are a very minor corner of the oil and gas giant's empire. Oczkowski described the potential application actionable data scraped from Facebook users as potentially "endless".