Twitter. From a genuinely open and global platform which pretty much single-handedly created a new market segment, to dogmatic SJW-infected thought police with no transparency or objectivity in how they operate. Gab is the closest we have come to a viable alternative at scale, but between industry-wide bullying to shut them down and their own short sighted inability to handle their own growth, Twitter still has an outright monopoly on their segment and no shame about abusing that position.