December 22, 2020 published at 5:13 AMReuters FILE PHOTO: A Microsoft logo is seen in Los Angeles, California US on November 7, 2017. Reuters Tech giants including Microsoft and Google on Monday joined Facebook’s legal battle against hacking company NSO, filing an amicus brief in federal court that warned that the Israeli firm’s tools were “powerful, and dangerous.” The brief, filed before the US Court of Appeals for the Ninth Circuit, opens up a new front in Facebook’s lawsuit against NSO, which it filed last year after it was revealed that the cyber surveillance firm had exploited a bug in Facebook-owned instant messaging program WhatsApp to help surveil more than 1,400 people worldwide.