While alternative media have long been playing important roles in the politics of protests and resistance in many countries, the Internet has led to the emergence of online alternative media and arguably expanded the reach of such outlets. This article focuses on the audience of Internet alternative media. It examines the factors associated with usage and whether and how usage relates to political participation. Analysis of survey data (N = 1,018) in Hong Kong shows that, not surprisingly, Internet alternative media usage was driven by preexisting political attitudes and critical views toward the mainstream media. But social media usage could also drive alternative media usage even among people who did not hold congruent preexisting attitudes. Meanwhile, alternative media usage leads to protest participation and support for unconventional protest tactics. The study thus provides empirical evidence regarding how Internet alternative media can facilitate the formation of an active online counterpublic and the role of social media in potentially enlarging the counterpublic.