Focusing on regime-threatening protests, Chapter 5 explores how and why antagonistic informal norms—characterized by transgressive resistance and unlawful repression—come to the fore and examines their undermining impact on regime legitimacy and stability. The analysis draws on three high-profile cases of regime-threatening protests—ethnic unrest in Xinjiang (China’s far west), protest by the Falun Gong (a quasi-religious group), and the Charter 08 campaign (pro-democracy resistance). Each of these protests involved one type of political grievance or another that overstepped the official limits; in each case, officials responded with resolute repression, through lawful and unlawful means. By reviewing the interactions of challengers and the state over the course of history, this chapter demonstrates that when conflicts and grievances are mixed with such factors as ethnicity, religion, ideology, a history of animosity, and international linkage, the chance that antagonistic informal norms will play out increases and contention of such kind frequently sets in motion a vicious cycle of repression and transgression, thereby intensifying conflict and challenging regime stability.