New literacies research and theory touts the advantages of participatory cultures where youth collaborate, connect, and share knowledge. However, these practices assume a certain level of trust. With a lens that combines sociological theories of trust and a new literacies theory of participatory culture, this paper draws on two studies of youth literacies practices. The participants represent urban and suburban as well as online and offline contexts. Findings bring to bear the centrality of trust to decisions and choices when participating in these communities, pushing research to consider trust and mistrust more thoroughly when theorizing benefits of participatory cultures.