The personal data of over 50 million Facebook users was mishandled in a massive political advertisement campaign.

Facebook is by far the world’s most popular social media service, with 2.19 billion active users as of March 31, 2018. On March 17, 2018, the New York Times revealed how Cambridge Analytica misused the personal data of over 50 million Facebook users in order to sell targeted advertisements during the 2016 presidential election. Zuckerberg testified before congress on April 10, 2018, admitting that his company mishandled personal information.

Mark Zuckerberg began attending Harvard University in 2002 where he coded and created what eventually became facebook.com.

Zuckerberg and Facebook are not strangers to controversy. Zuckerberg was sued over the website immediately after it was created by Cameron and Tyler Winklevoss, who claimed that he had stolen their idea for a Harvard-exclusive social network. The lawsuit was settled, and Zuckerberg was allowed to keep Facebook. Shortly thereafter, Zuckerberg was sued by his former business partner and Facebook co-founder Eduardo Saverin, which was also settled.

Cambridge Analytica is a data and analytics firm that was hired by President Donald Trump’s electoral campaign to better target and advertise to voters online. They have previously worked with other politicians, including with Ted Cruz’s unsuccessful presidential campaign. In an interview on October 22, 2016, CEO Alexander Nix said, “The traditional model where 50 million people receive the same blanket advert is being replaced by extremely individualistic targeting.”

Cambridge Analytica went far beyond simple targeted advertisement, however. Nix added that, “Today in the United States we have somewhere close to four or five thousand data points on every individual. So we model the personality of every adult across the United States, some 230 million people.”

According to Recode, these data points were mined from underprotected user data which stemmed from 270,000 users who logged into a third-party app with their Facebook account. By logging in, they exposed not only their personal data but the personal data of their Facebook friends, leading to over 50 million users’ personal information being accessed. The app’s creator, Cambridge University psychology lecturer Aleksandr Kogan, then sold the harvested data to Cambridge Analytica.

Facebook is now facing at least 36 class action lawsuits alleging “negligence, invasion of privacy, and violation of state consumer protection laws and the federal Stored Communications Act,” according to Fortune. The lawsuits argue that Facebook should have protected their data from something so simple.

Facebook maintains its innocence, saying that the data was harvested from users who willingly gave up their privacy. Kogan argues the same point, saying in an interview with CBS, “[Access to friends’ user data] was not a special permission you had to get. This was just something that was available to anybody who wanted it who was a developer.”

Silicon Valley Business Journal reports that when questioned about his company’s responsibility to protect users, Zuckerberg said, “I think the mistake we made is viewing our responsibility as just building tools, rather than viewing our whole responsibility as making sure those tools were used for good.” Despite the negative press, Facebook stock actually rose during the testimony.

Politico reports the White House has stated the campaign did not use Cambridge Analytica’s data, and that they had minimal involvement in the election. White House insider Jared Kushner has previously praised the campaign’s digital ability on Facebook.

After months of turmoil and the departure of Nix, The New York Times reported that Cambridge Analytica would file for bankruptcy. In a statement on their website, Analytica cited “unfounded reports” and lost clients as causes of their bankruptcy.

While it is not yet certain whether or not this issue of data misuse will create a lasting change, this scandal has already created a great deal of dialogue about privacy and the role of social media in daily life. Only time will tell if Cambridge Analytica will be the final straw for online privacy legislation.