Network effects: You may swipe out if you like but can never leave Premium Share Via Read Full Story Tesla and SpaceX founder Elon Musk had a terse tweet for his 48 million followers: “Use Signal". Edward Snowden, the world’s most famous whistleblower and privacy advocate clarified in a tweet of his own: “That’s @signalapp, for those who don’t speak Elon." Someone asked him why use Signal, and he had a simple though chilling response: “I use it every day and I’m not dead yet." The implication being that if he used WhatsApp, people would have been able to trace him through its owner, Facebook, a company admired and reviled in equal measure.