This PhD thesis investigates how communities living in exile use digital media to mobilise for truth-seeking and legal justice on behalf of home-country causes. Through case studies of responses to rights violations in Eritrea and Sudan, it examines how activists-in-exile use digital media to organise transnational networks, reshape conflict narratives and raise rights claims, and enact acts of citizenship. Firstly, it explores the conditions that activate activists’ agency in participating in political mobilisation in exile through spatial, relational, and affective lenses, and it interrogates what enhances the political participation of communities affected by crisis. Secondly, by delving into the content and networks of activist campaigns, it interrogates what demands were raised in hashtag campaigns as well as what tactics were used to generate awareness on the human rights abuses committed in Sudan as well as in Eritrea, and to exert pressure on the international community. Finally, it examines activist practices and strategies through two specific interrelated communicational dimensions of their media work, using two conceptual categories that stem from reference literature: (i) media practices, and (ii) repression and disruption. To understand these issues, this thesis brings together literature that investigates the relationship between migration, digital technologies and transnational political mobilisation. Based on a multiple-method design that employs offline and online research methods (semi-structured interviews, ethnographic research and network analysis) this thesis contributes new empirical knowledge regarding the motivations, strategies, and practices of activists-in-exile. Specifically, my objective is to develop new knowledge about (i) the factors that contribute shape and advance transitional justice within exiled communities; (ii) the taxonomy of media practises and how they align to human rights strategies and tactics; and (iii) the risks and opportunities of these practises including the implications of platform content moderation and emergent practises to preserve at-risk human rights–related content.