Violent crime levels have been going down in America. But people perceive those levels as going up. That contradiction is nothing new. But it could be dramatically exacerbated by the proliferation of a new kind of social network that connects you to your neighbors — without you ever leaving the house. Rani Molla in Recode: The rise of fear-based social media like Nextdoor, Citizen, and now Amazon’s Neighbors. In theory, these apps are providing a layer of protection. But they could also be creating a much thicker layer of fear.