The US District of Columbia is suing Meta chief Mark Zuckerberg, seeking to hold him personally liable for the Cambridge Analytica leaks, a privacy breach of millions of Facebook users' personal data that became a major corporate and political scandal.
Attorney-General Karl Racine filed the civil lawsuit against Zuckerberg in DC Superior Court.
The suit maintains 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 the data-mining firm.
Cambridge Analytica gathered details of upto 87 million Facebook users without their permission.
Their data is alleged to have been used to manipulate the 2016 presidential election.
Zuckerberg, who co-founded Facebook and has headed its board since 2012, controls more than 50 per cent of the company'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 network giant has nearly three billion users worldwide, with its owner Meta valued at more than $US500 billion ($A705 billion).
Racine is seeking damages and penalties from Zuckerberg.
Meta spokesman Andy Stone declined to comment. Meta, the parent of Facebook, Instagram and WhatsApp, is based in Menlo Park, California.
Meta, 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 Racine's suit brought the rare action of a regulator specifically aiming at a big tech CEO.
Zuckerberg directly participated in decision-making that allowed the massive data breach, while Facebook misled users with claims of privacy protection, the suit alleges.
Racine tried last year to add Zuckerberg as a defendant in his ongoing suit against Facebook over Cambridge Analytica from 2018.
But a Superior Court judge thwarted that attempt in March, saying Racine had waited too long to add the company's founder.
Now, Racine is asserting thousands of documents he has since gained access to in the case establish Zuckerberg's direct participation in decision-making on Cambridge Analytica.
A year ago, Racine sued Amazon, accusing the online retail giant of anti-competitive 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 Racine has asked for it to be reconsidered.
Australian Associated Press