Across China's vast digital commons, a quiet but consequential tightening is underway — social media platforms are narrowing the bandwidth of permissible expression, reshaping the informational world of hundreds of millions of people. Driven by intensifying regulatory pressure from Beijing and a competitive race among platforms to demonstrate compliance, the shift represents not merely a policy adjustment but a philosophical contraction of what it means to speak and be heard online. The deeper question this moment raises is one humanity has wrestled with across every era of communication: who