“In another turn of events, Mark Zuckerberg also respects his own privacy, by using a chat app that has end-to-end encryption and isn’t owned by @facebook,” Dave Walker wrote on Twitter.

https://www.news18.com/news/buzz/signal-takes-jibe-at-mark-zuckerberg-after-facebook-ceo-found-using-whatsapps-rival-app-3612293.html