ProPublica describes itself as 'an independent, nonprofit newsroom that produces investigative journalism with moral force.
Their March 2019 report said Mark Zuckerberg, the CEO of Facebook, guaranteed the privacy of WhatsApp users.
"I believe the future of communication will increasingly shift to private, encrypted services where people can be confident what they say to each other stays secure and their messages and content won't stick around forever. This is the future I hope we will help bring about. We plan to build this the way we've developed WhatsApp," Zuckerberg said.