Researchers studying Internet activism have disagreed over the extent to which Internet usage alters the processes driving collective action, and therefore also over the utility of existing social movement theory. We argue that some of this disagreement owes to scholars studying different kinds of Internet activism. Therefore, we introduce a typology of Internet activism, which shows that markedly different findings are associated with different types of Internet activism and that some types of Internet activism have been studied far more frequently than others. As a consequence, we ask an empirical question: is this skew in the selection of cases, and hence apparent trends in findings, a reflection of the empirical frequency of different types of Internet activism? Troublingly, using unique data from random samples of websites discussing 20 different issue areas commonly associated with social movements, we find a mismatch between trends in research cases studied and empirical frequency.