Almost ten years have passed since the events of September 11, 2001 during which time the events have been interpreted and reinterpreted. This study examines how the victims and perpetrators of political violence are continually defined and redefined by social actors with different relationships to the events. Drawing on comparative case studies, the research elucidates the frames used by French, Brazilian, and American participants of online communities to articulate competing constructions of justice, responsibility, and victimhood. Comparing immediate response to September 11, 2001 with memorialisations of the events over time, the study identifies commonalities and differences across the three case studies. The work explores how these three groups negotiate 9/11 using ideological discourse regarding moral accounting and associated identity work related to national, transnational, and supranational identity categories. Across the cases, individuals employ identity categories as boundary markers to assess blame and to call for retribution against various social actors. In response, others negate or redefine identity categories to efface differences between the “us” and the “them.” However, even as they engage in parallel processes, at the same time, French, Brazilian, and American nationals employ particular cultural tropes to bolster their views. The research compares the metaphors, vocabularies, and cultural “lenses” through which they judge acts of political violence, as well as the drawing of moral and social boundaries. In identifying these trends, the work sheds light on enduring questions addressing the use of ideology to legitimise or delegitimise acts of political violence, including the events of 9/11.