Technology use is increasingly characterized by both critical mindsets and participatory practices. Yet, our current media literacy frameworks, critical media literacy and participatory media literacy, fail to account for and understand the nature of these practices because they are happening in situ. Arguing that these frameworks might be synthesized to understand emergent online practices, this article introduces the notion of hacker literacies: empowered participatory practices, grounded in critical mindsets, that aim to resist, reconfigure, and/or reformulate the sociotechnical digital spaces and tools that mediate social, cultural, and political participation in the 21st century. The article grounds this concept in a number of recent cases, including the Arab Spring and Occupy Wall Street movements, the creation of the hashtag on Twitter, and public reactions to Facebook’s privacy policy changes. These examples illustrate the ways users of new media do not take for granted the design of these new modes of participation nor the intentions and interests of their creators. Their understanding of the malleability of sociotechnical spaces and consequent actions often result in the reformulation of these spaces, a process the author argues will be crucial if there is to be a more fluid and equal distribution of media power in the digital age.