The United States Supreme Court has allowed the WhatsApp messaging platform to pursue a lawsuit against Israel’s NSO Group, which makes the Pegasus spyware linked to state surveillance of journalists, human rights advocates and dissidents around the world.

The top court’s justices on Monday left in place lower court rulings against the Israeli company, which had argued it should be recognised as a foreign government agent and, therefore, be entitled to immunity under US law limiting lawsuits against foreign countries.

WhatsApp, which is owned by Meta and is among a number of tech companies and individuals pursuing legal action against the Israeli firm, has alleged that NSO Group surveilled about 1,400 people through the messaging platform.

The company’s 2019 lawsuit seeks to block the NSO Group from Meta platforms and servers and recover unspecified damages.

Meta, which owns both WhatsApp and Facebook, on Monday welcomed the Supreme Court’s decision to deny what it called a “baseless” appeal.

“NSO’s spyware has enabled cyberattacks targeting human rights activists, journalists and government officials,” Meta said in a statement. “We firmly believe that their operations violate US law and they must be held to account for their unlawful operations.”

The administration of President Joe Biden had previously recommended that the court turn away the appeal, with the Department of Justice arguing that “NSO plainly is not entitled to immunity here”.

The US Department of Commerce in 2021 blacklisted the Israeli firm for complicity in “transnational repression”, a move that limited NSO Group’s access to US technology.

WhatsApp has alleged that at least 100 of the targeted users connected to its lawsuit were journalists, rights activists and civil society members.

An investigation published in 2021 by 17 media organisations, led by the Paris-based non-profit journalism group Forbidden Stories, found that the spyware had been used in attempted and successful hacks of smartphones belonging to journalists, government officials and human rights activists on a global scale.

Palestinian rights workers, Thai democracy activists, El Salvador media workers and the inner circle of murdered Saudi journalist Jamal Khashoggi were allegedly among those targeted by state actors using Pegasus spyware.

“Today’s decision clears the path for lawsuits brought by the tech companies as well as for suits brought by journalists and human rights advocates who have been victims of spyware attacks,” Carrie DeCell, a senior staff attorney at the Knight First Amendment Institute who is representing journalists in a separate lawsuit against NSO Group, said on Monday.
For its part, the NSO Group has argued that Pegasus helps law enforcement and intelligence agencies fight crime and protect national security. It has said the technology is intended to help catch “terrorists”, paedophiles and criminals.

The firm, which does not disclose its clients, has maintained that only law enforcement agencies can purchase the product and all sales are approved by Israel’s Ministry of Defense. It has said it does not have control of how the technology is used after it is sold.

After Monday’s ruling, the Israeli company said in a statement: “We are confident that the court will determine that the use of Pegasus by its customers was legal.”

The NSO Group also is being sued by iPhone maker Apple, which has accused the firm of violating its user terms and services agreement by breaking into its products.

Apple has previously called NSO’s employees “amoral 21st century mercenaries”.