Mediatized hate speech fuelled the genocide against the Tutsis in Rwanda nearly three decades ago, yet anti-Tutsi rhetoric is still circulating in the Great Lakes region, albeit under a radically changed media and political landscape. Social media and online platforms facilitate the proliferation of inflammatory and discriminatory discourses whose impact on violent conflict remains uncertain. This study examines the phenomenon by focusing on anti-Banyamulenge and anti-Tutsi hate speech in the context of resurgent violent armed conflict in the highlands of Eastern South Kivu province of the Democratic Republic of Congo (DRC). It first explores the history of the Banyamulenge in the DRC, highlighting contestations of their identity and belonging as well as their experiences and positionality in the current cycle of atrocious conflicts. It then documents and analyzes the content of hate speech and conspiracy theories circulating in audio, video, and text messages in multiple languages, and identifies the actors involved in their dissemination. The analysis unpacks how social media platforms facilitate interactions between diverse actors, including leaders of armed groups, public officials, and diaspora communities. It argues that novel transboundary networks of identity are emerging where hateful narratives and conspiracy theories are created, refined, and disseminated to larger audiences. These self-reinforcing networks diffuse incendiary nativist discourses, anti-Tutsi sentiments, dehumanizing language, and calls for genocide reaching from global to local terrains.