In Singapore, the average social media penetration rate is 70 per cent, one of the highest in Asia, with Facebook being the most popular, followed by Instagram and Twitter. With the mass adoption of social media, much has been said about the robustness and the inclusiveness of the online space as a sustainable public sphere. The chapter provides some propositions by which social media shape collective action and social movements. The small-world concept developed by Chatman may provide further clues for understanding the function of online enclaves as multiple publics, their use of social media, and their implications for social movement. With social media bringing about 'new' kinds of spaces in which online discourse about salient issues can flourish, they can function as 'weak publics', which function as spaces of deliberation and discourse, participated in by private individuals and performing discursive checks on the decisions made by the state.