Facebook data scandal: What you need to know

Facebook has some explaining to do. To be more precise, the social media giant has to explain how personal data from up to 87 million users was harvested by Cambridge Analytica and used to further political agendas in the UK, US and even Kenya.

Lawmakers on both sides of the Atlantic have made sure Facebook founder and CEO Mark Zuckerberg testifies as to whether the networking platform failed to protect user data. The scandal has also prompted campaigns urging users to delete their Facebook accounts.

Read more: 5 things to know about the world's biggest social network

How we got here:

• The New York Times and UK-based Observer reported that more than 50 million Facebook users had their data harvested by Cambridge Analytica in what has been described as the social media platform's largest data breach to date. Weeks later, Facebook admits up to 87 million accounts may have been affected.
• Cambridge Analytica reportedly used the data to target users with personalized political ads to further Donald Trump's 2016 presidential bid and the pro-Brexit campaign.
• It claimed that it "fully complies with Facebook's terms of service," denying any wrongdoing in harvesting data from the social media platform to further clients' political projects.

• Facebook CEO Mark Zuckerberg said his company will implement three new measures to better protect user data after the revelations, including banning developers that misused personal data and further restricting developer access to user data.

Read more: Facebook's Mark Zuckerberg admits 'mistakes' in Cambridge Analytica scandal

Key facts:

• Trump's former far-right political strategist Stephen Bannon reportedly oversaw one of Cambridge Analytica's programs which created voter profiles based on data garnered from Facebook. He served as the company's vice president and secretary before joining Trump's campaign in 2016.
• The revelations prompted a sell-off of Facebook stocks and those of other social media platforms, knocking off $50 billion (€40 billion) from Facebook's market value and roughly $9 billion from Zuckerberg's personal wealth, according to Forbes. The company later recovered losses.
• Cambridge Analytica is partially owned by American businessman Robert Mercer, who is known for backing conservative causes. The company, which says it "uses data to change audience behavior," is the subject of ongoing criminal investigations for its role in the Brexit vote and the US presidential election.
• The company announced in May that it would close its doors, saying a "siege of media coverage has driven away virtually all of the company’s customers and suppliers."

Read more: Who are the Mercers? What you need to know about Breitbart's backers

Key quote:

Christopher Wylie, the whistleblower who worked alongside Cambridge University researcher Aleksandr Kogan to garner the data for Cambridge Analytica, told the Observer:

• "We exploited Facebook to harvest millions of people's profiles. And built models to exploit what we know about them and target their inner demons. That was the basis the entire company was built on."

Wylie has testified to UK lawmakers on Cambridge Analytica's activities, including its influence on the 2016 Brexit vote, and has said he would also testify to US lawmakers.

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