Sociologists of culture studying “fan activism” have noted an apparent increase in its volume, which they attribute to the growing use of the Internet to register fan claims. However, scholars have yet to measure the extent of contemporary fan activism, account for why fan discontent has been expressed through protest, or precisely specify the role of the Internet in this expansion. We argue that these questions can be addressed by drawing on a growing body of work by social movement scholars on “movement societies,” and more particularly on a nascent thread of this approach we develop that theorizes the appropriation of protest practices for causes outside the purview of traditional social movements. Theorizing that the Internet, as a new media, is positioned to accelerate the diffusion of protest practices, we develop and test hypotheses about the use of movement practices for fan activism and other nonpolitical claims online using data on claims made in quasi-random samples of online petitions, boycotts, and e-mailing or letter-writing campaigns. Results are supportive of our hypotheses, showing that diverse claims are being pursued online, including culturally-oriented and consumer-based claims that look very different from traditional social movement claims. Findings have implications for students of social movements, sociologists of culture, and Internet studies.