Tech company WhatsApp has launched an unprecedented lawsuit against an Israeli cyber weapons firm which it has accused of being behind secret attacks on more than 100 human rights activists, lawyers, journalists, and academics in just two weeks earlier this year.

WhatsApp said it believed the technology sold by NSO was used to target the mobile phones of more than 1400 of its users in 20 different countries, including human rights lawyers, prominent religious figures, and journalists during a 14-day period from the end of April to the middle of May.

WhatsApp’s lawsuit, filed in a California court on Tuesday, has demanded a permanent injunction blocking NSO from attempting to access WhatsApp computer systems and those of its parent company, Facebook.