Studies examining preservice teachers' (PSTs) experiences with microblogging and activities that buttress and promote their social justice development have largely occurred in isolation from one another. To that end, this study examines in what ways pairing the popular social networking website Twitter with readings from a young adult literature course helped PSTs cultivate their awareness of and positionalities related to the social justice issues discussed in the course--and ones they will confront in their classrooms. Although students noted that engaging in this new dialogic space afforded certain benefits, the data suggest that PSTs encountered a variety of obstructions as they worked to develop and articulate their social-justice-oriented positionalities, including difficulty extending in-class conversations and trouble negotiating the social dimensions of Twitter. In examining the intersection between Twitter and its conduciveness to support PSTs' social justice positionalities, the findings suggest that, despite its popularity, the forum did not prove to be an organic medium for students to engage social justice issues. Findings imply that teacher educators interested in utilizing microblogging to foster PSTs' social awareness and growth should utilize Twitter as but one of many pedagogical tools to assist students in developing their social justice positionalities.