Pressure on Facebook

Share price tumbles as politicians call for explanation of data use

FACEBOOK chief executive Mark Zuckerberg is facing calls from US and European politicians to explain how a consultancy that worked on President Donald Trump’s election campaign gained improper access to data on 50 million Facebook users.

The social media giant’s shares closed down nearly 7 per cent, wiping nearly $US40 billion off its market value as investors worried that new legislation could damage the company’s advertising business.

“The lid is being opened on the black box of Facebook’s data practices, and the picture is not pretty,” said Frank Pasquale, a University of Maryland law professor who has written about Silicon Valley’s use of data.

Politicians in the US, Britain and Europe have called for investigations into media reports that political analytics firm Cambridge Analytica harvested the private data on more than 50 million Facebook users to develop techniques to support Trump’s 2016 presidential election campaign.

The scrutiny presents a fresh threat to Facebook’s reputation, which is already under attack over Russia’s alleged use of Facebook tools to sway US voters with divisive and false news posts before and after the 2016 election.

Facebook said on Monday it had hired digital forensics firm Stroz Friedberg to carry out a comprehensive audit of Cambridge Analytica, which had agreed to comply and give the forensics firm complete access to their servers and systems.

Cambridge Analytica said it strongly denied the media claims, and that it deleted all Facebook data it obtained from a third-party app in 2014 after learning the information did not adhere to data protection rules.

But further allegations about the firm’s tactics piled up on Monday, as Channel 4 News, a British broadcaster, published video of Cambridge Analytica executives talking about using bribes, former spies and Ukrainian sex workers to entrap politicians.

Facebook was already facing calls for regulation from US Congress.