Open this photo in gallery: Elon Musk gestures as he attends the Viva Technology conference dedicated to innovation and startups at the Porte de Versailles exhibition centre in Paris, on June 16.GONZALO FUENTES/Reuters For all its faults, social media offered great promise: Democratization of voice and a platform for all, gatekeepers be damned (with exceptions to keep things safe). Here was a way, beyond the letters-to-the-editor page, to scream into the void with results; someone might hear you and engage. And for better or – with increasing frequency – worse, it has changed the game. Facebook went from being a...