The Supreme Court Monday left in place a decision allowing Meta Platforms to sue NSO Group for allegedly installing Pegasus malware on the phones of WhatsApp users.
As is customary, the court did not give a reason for its refusal to hear NSO's appeal.
The move means the Israeli company NSO Group must now face claims that it violated federal and California anti-hacking laws, as well as WhatsApp's terms of service.
The battle between the companies stemmed from reports that the Israeli company installed Pegasus malware on the phones of approximately 1,400 WhatsApp users, including human rights leaders, journalists, government officials, and diplomats.
Meta sued NSO in October of 2019 over the alleged spyware.
NSO argued that it was protected by the Foreign Sovereign Immunity Act, which generally immunizes foreign governments from civil lawsuits. The company claimed that because it acted as an agent for other countries, it was entitled to the same immunity they would have.
Last November, a three-judge panel of the 9th Circuit sided against NSO, ruling that the Foreign Sovereign Immunity Act protects "foreign states," but not private companies that license technology to the government.
“Whatever NSO’s government customers do with its technology and services does not render NSO an 'agency or instrumentality of a foreign state,' as Congress has defined that term," 9th Circuit Judge Danielle Forrest wrote in an opinion joined by Judges Mary Murguia and Ryan Nelson. "Thus, NSO is not entitled to the protection of foreign sovereign immunity."
NSO argued to the Supreme Court that the lower court's ruling could result in lawsuits against U.S. contractors in other countries.
The Biden administration urged the Supreme Court to reject NSO's position, noting that no other countries supported NSO's claim to immunity.
“NSO has not even identified the states for which it claims to have acted as an agent,” the Solicitor General wrote in papers filed in November.
Meta is not the only company suing NSO. In late 2021, Apple alleged in a federal lawsuit that NSO violated a federal anti-hacking law by accessing the operating system on mobile phones to install Pegasus.
Journalists with the El Salvador-based news organization El Faro are also suing NSO for allegedly installing Pegasus spyware on their iPhones.