LONDON (AP) — The co-founder of WhatsApp, which was acquired by Facebook four years ago for $19 billion, has joined the movement to delete Facebook.
Brian Acton tweeted: "It's time. #deletefacebook."
That hashtag has been trending since reports surfaced in recent days regarding the improper use of personal information on Facebook by Cambridge Analytica, a political research firm used by the Trump campaign before the election.
Facebook CEO Mark Zuckerberg has remained silent as nearly $50 billion in market capitalization of his company has been wiped out with investors fearing new oversight by government regulators.
British Prime Minister Theresa May says allegations that Facebook users' data was improperly used by political campaigns are "very concerning."
May says she expects Facebook and data analytics firm Cambridge Analytica to "comply fully" with British authorities investigating how personal information was obtained and used.
May told lawmakers in the House of Commons that "people need to have confidence in how their personal data is used."
Authorities in Britain and the United States are investigating the alleged improper use of data harvested from tens of millions of Facebook users by Cambridge Analytica, which worked on U.S. President Donald Trump's 2016 campaign.
May said that "as far as I'm aware" the British government has no contracts with Cambridge Analytica or its parent company, SCL.
A British consultant says Cambridge Analytica approached him before Romania's 2016 parliamentary elections to work for the Social Democratic Party.
Rupert Wolfe Murray told The Associated Press on Wednesday that Mark Turnbull, a senior official at Cambridge Analytica, contacted him in August 2016.
He cited an email where Turnbull wrote: "What we have offered is to embed a two-person team into the current campaign team... to provide ongoing strategic advice and assistance across the campaign.... over the next 2-3 months."
Wolfe Murray said he declined the offer because he does not work for political parties. It was unclear whether Cambridge Analytica played a role in the Dec. 2016 elections, where the Social Democrats won about 46 percent of the vote. The Liberals came second with 20 percent.
Separately, investigative platform RISE project reported that SCL Group, a British strategic communication company affiliated to Cambridge Analytica, set up an office in Romania in 2011.
A sell-off in Facebook shares is heading into the third consecutive day, with almost $50 billion in market capitalization evaporating since the start of the week.
The stock fell 1.5 percent before the opening bell Wednesday and, after falling 9 percent, it's one of the worst weeks in company history.
Governments on both sides of the Atlantic are calling for CEO Mark Zuckerberg to testify on the issue, but he has been silent since a story broke Friday about how a firm tied to the campaign of Donald Trump improperly lifted data on 50 million Facebook users.
That firm, Cambridge Analytica, suspended CEO Alexander Nix pending an investigation.
Company filings show that Trump-affiliated data-mining firm Cambridge Analytica has a link to a Chinese security and logistics company run by Erik Prince, the former mercenary who founded private military company Blackwater.
British corporate records show that Alexander Nix, the suspended chief executive of Cambridge Analytica, is also director of a company called Emerdata Ltd. that was incorporated in August 2017.
Other Emerdata directors include people associated with Cambridge Analytica, along with Johnson Ko Chun Shun, who was appointed in January.
Ko is also deputy chairman of Hong Kong-based Frontier Services Group, whose chairman is Prince.
FSG has attracted attention because of concerns Prince plans to provide special forces veterans to assist Chinese companies investing in risky locations overseas.
China's biggest state-owned company, Citic, is a major FSG shareholder.
The Cambridge University researcher who developed an app used by Cambridge Analytica to harvest data from millions of Facebook users claims he has been made a scapegoat.
Alexandr Kogan told BBC on Wednesday he believed all the information he provided was obtained legitimately. He said he was approached by Cambridge Analytica, which is being investigated by British and U.S. authorities for possible misuse of data.
He said: "They approached me. In terms of the usage of Facebook data they wrote the terms of service for the app, they provided the legal advice that this was all appropriate."
Kogan admitted he did not ask enough questions about the data use and did not have a lawyer review the agreement.
Cambridge Analytica has suspended its top executive as possible misuse of data is checked.