But you won't be able to reactive your account or access any of the content or information you've shared, if you change your mind.

Dr Shashi Jayakumar of the S. Rajaratnam School of International Studies warned that Singapore's close neighbours may already be seeing disinformation tactics being deployed internally. Stamos later said that he would not leave Facebook, but shift priorities to "spending more time exploring emerging security risks and working on election security". She also asked Grassley to seek testimony from Cambridge Analytica CEO Alexander Nix, who was suspended on Tuesday pending a probe. It said Kogan has given his verbal agreement to do so and Wylie has declined.

"New Yorkers deserve answers, and if any company or individual violated the law, we will hold them accountable", Schneiderman said today. The company's forecast for the fourth quarter also came up short of estimates. The tech company holding that title in 2018 is Facebook. "Privacy and data protections are fundamental to every decision we make".

What's harder to quantify but no less damaged is the image of Zuckerberg within the political world.

The questions of data privacy thrown up by the scandal strike at the heart of Facebook's business, which relies on more than 1.4 billion users engaging with the platform each day. Instead, you'll need to sign up for the service directly with a unique log in.

Another of the firm's executives, head of data, Alex Tayler, bragged that data had snatched victory for Mr Trump from his rival Mrs Clinton.

Fear of increased regulation hurt other social media firms on Tuesday. Political persuasion that used to take place in the open, in Congress or on the hustings.

"This story comes on the back of increasing scrutiny and societal unease with FB's potential impact on kids as well as increasing concerns around the power of mega cap Internet names, setting the stage for deeper investigation", Deutsche Bank analyst Lloyd Walmsley wrote in a note, keeping his "buy" rating on Facebook stock.

However, after the firm missed the deadline, Denham told Britain's Channel 4: "I'll be applying to the court for a warrant". The average person opening his Facebook feed on a smartphone does not know he has been "targeted" as a person who might read about a sting operation involving Ukrainian girls.

In fact, Oxford Analytica says it entered into a trademark dispute with Cambridge Analytica last year, and argues that it has held a trademark for the word Analytica for more than 20 years.

The managing director of Cambridge Analytica's political division, Mark Turnbull, was also shown saying the company could create proxy organisations to spread negative material about opposition candidates online without being traced. It was unclear late on Tuesday whether it had obtained it.

CA was created initially with a focus on US elections, with US$15 million (S$19.8 million) in backing from billionaire Republican donor Robert Mercer and a name chosen by the future Trump White House adviser Stephen Bannon.

It was naive of me, perhaps, but I couldn't work it out when I first encountered the phenomenon. Facebook has since suspended both the consulting firm and SCL (Strategic Communication Laboratories), a government and military contractor.

The event took place days after shootings at a high school in Parkland, Fla., left 17 people dead. Kogan was not immediately reachable for comment.

The reports say the firm exploited private social media activity to help allow the Trump campaign to better target voters by profiling their behaviour and personalities ahead of the U.S. election.