Facebook founder Mark Zuckerberg is being sued by the US District of Columbia which is seeking to hold him personally liable for the Cambridge Analytica scandal that breached millions of people's personal data.
The political consultancy was accused in 2018 of illegally harvesting the personal data of as many as 87 million Facebook users.
The data was alleged to have been used to manipulate the 2016 US presidential election.
D.C. Attorney General Karl Racine filed a civil lawsuit against Mr Zuckerberg in the D.C. Superior Court. He is seeking damages and penalties from Mr Zuckerberg.
The lawsuit maintains that Mr Zuckerberg directly participated in important company decisions and was aware of the potential dangers of sharing users' data, such as occurred in the case involving data-mining firm Cambridge Analytica.
Mr Zuckerberg, who co-founded Facebook and has headed its board since 2012, controls more than 50% of Facebook's voting shares and "maintains an unparalleled level of control over the operations of Facebook as it has grown into the largest social media company in the world," the lawsuit says.
The social media giant has nearly three billion users worldwide.
Meta, Facebook's parent company which also owns Instagram and WhatsApp, has a market value of more than $500 billion (£397bn).
Meta Platforms spokesman Andy Stone declined to comment.
It comes as Google, Amazon, and Apple have been targeted in legal actions in recent years by federal regulators and state attorneys general of both parties accusing the tech behemoths of market dominance and abuse.
But this is the first lawsuit aimed specifically at a Big Tech CEO.
Mr Racine tried last year to add Mr Zuckerberg as a defendant in his ongoing suit against Facebook over Cambridge Analytica from 2018.
But a D.C. Superior Court judge thwarted that attempt in March, saying that Racine had waited too long to add him. "What value does it add to name him? There's no more relief for the consumers of the District," Judge Maurice Ross said at the time.
Now, Mr Racine is asserting that thousands of documents he has since gained access to in the case establish Zuckerberg's direct participation in decision-making on Cambridge Analytica, and he is therefore suing Zuckerberg directly.
A year ago, Mr Racine sued Amazon, accusing the online retail giant of anticompetitive practices in its treatment of sellers on its platform. The practices have raised prices for consumers and stifled innovation and choice in the online retail market, he alleged. Amazon rejected the allegations.
That suit was dismissed by the court and Mr Racine has asked for it to be reconsidered.