This is a book about Weibo, a leading Chinese micro-blogging platform. The dynamics of Weibo, especially the flow of news within and outside its domain, reflects the dynamics of contemporary social transition in China. This book aims to capture the highs and lows of this social media platform that, since its launch in August 2009, has substantially altered the ways in which Chinese people respond to ongoing public events and remember them. The information updates on this platform involved extensive discussions intermingled the “now” and “then” aspects of these events, with a blending of local and global participation in the ensuing information flow. At that time, journalists and media professionals were at the forefront of utilizing Weibo as a news platform. They brought past events to Weibo while reporting and discussing the current news; they made efforts to keep the public remembering what was happening, against attempts to censor their stories; they also became actively involved in the investigation of past events. It is the presence of such an anxiety over forgetting that motivated this research on the construction of collective memory in social media platforms.