This study explores how ELL students' parents participated in a blog-mediated English language arts curriculum in a second grade classroom at a U.S. urban school, and how they supported their children's learning of school-based writing. Adopting ecological perspectives on technological affordances, this study views digital literacy as discursive practices that are shaped by one's social, cultural, and political access, as well as material access. The findings indicate that parents used blogging to support their children's academic and social goals, bringing expanded audiences and meaningful purposes to school writing. However, their linguistic and cultural capital related to Web 2.0 technologies generated different levels of participation and affordances. The study contends that parental involvement through Web 2.0 technologies needs to be critically examined, in consideration of discursive factors operating in the contexts in which those technologies are used.