Brian Acton (Messaging / Privacy Tech) at WhatsApp / Signal — Menlo Park, United States

Brian Acton co-founded WhatsApp with Jan Koum and sold it to Facebook for $19 billion, famously having been rejected by both Facebook and Twitter before that. After leaving Facebook over data privacy disputes, he donated $50 million to found the Signal Foundation, enabling the Signal encrypted messaging app to operate as a non-profit. His tweet "It is time. #deletefacebook" sparked a global campaign and solidified his status as a privacy advocate.