今年是中国1989年天安门民主运动的30周年纪念。当年，学生自发举行一系列游行示威，呼吁实施民主改革，中共领导人则选择使用武力镇压运动。中国红十字会称有2700名民众在武力镇压中身亡，但有不少研究机构指出死伤人数远不止这个。在2014年解密的一份美国政府机密文件显示，中国内部统计的死亡人数达10,454人。

今年是中國1989年天安門民主運動的30週年紀念。當年，學生自發舉行一系列遊行示威，呼籲實施民主改革，中共領導人則選擇使用武力鎮壓運動。中國紅十字會稱有2700名民眾在武力鎮壓中身亡，但有不少研究機構指出死傷人數遠不止這個。在2014年解密的一份美國政府機密文件顯示，中國內部統計的死亡人數達10,454人。

In this report, we reverse engineer three popular live streaming platforms (YY, Sina Show, and 9158) and find keyword lists used to censor chat messages. Tracking changes to the keyword lists over the past year gives an inside look into how these applications implement censorship

In this paper presented at USENIX FOCI 2015 we use reverse engineering to provide a view into how keyword censorship operates on four popular social video platforms in China: YY, 9158, Sina Show, and GuaGua. We also find keyword surveillance capabilities on YY. Our findings show inconsistencies in the implementation of censorship and the keyword lists used to trigger censorship events between the platforms we analyzed. We reveal a range of targeted content including criticism of the government and collective action. These results provide evidence that there is no monolithic set of rules that govern how information controls are implemented in China.