New York, Mar 24: Social networking giant Facebook has been slapped with four legal lawsuits within a week amid claims that UK-based analytical firm Cambridge Analytica is accused of harvesting millions of users' data from Facebook. A Facebook user named Lauren Price of Maryland filed a suit in San Jose on Tuesday on behalf of up to 50 million people whose data was used by Cambridge Analytica.

"It's a class action lawsuit that claims Facebook has "absolute disregard" for my personal data, despite allegedly stating it would not disclose data without permission or at least notice," said Price. The suit also noted that during the 2016 US presidential election, Price often saw political ads on her own Facebook feed. Individual shareholders in Facebook - Fan Yuan and Robert Casey, each filed their own class action lawsuit against its CEO Mark Zuckerberg and CFO David Wehner.

The plaintiffs seek to recover the losses incurred when Facebook's stock tanked this week, which cost the company nearly 10 percent of its market value, according to The Verge. A fourth lawsuit was filed by attorney Jeremiah Hallisey on Thursday in San Jose, on behalf of the Facebook's shareholders against Zuckerberg, COO Sheryl Sandberg, and board members.

The suit claims that the executives and board of directors failed to stop the data breach or tell users about it when it happened, and therefore "violated their fiduciary duty."

Hallisey is also asking for payment that restores the company shareholders to their previous positions and a court order for Facebook to improve its internal processes respectively. Cambridge Analytica is accused of harvesting personal data of Facebook users to influence elections in several countries including the US presidential elections. It suspended its chief executive, Alexander Nix, for the same.

The company, founded by Stephen K. Bannon and Robert Mercer, a wealthy Republican donor who has put at least USD 15 million into it, offered tools that could identify the personalities of American voters and influence their behaviour.

The so-called psychographic modelling techniques, which were built in part with the data harvested from Facebook, underpinned the company's work for then-Republican nominee and US President Donald Trump's campaign in 2016.

On Thursday, Zuckerberg said that he was sorry about the Cambridge Analytica scandal affecting "tens of millions" and that he would be "willing to testify before the US Congress." Both Cambridge Analytica and Facebook have denied any wrongdoing.