This paper provides analysis and insight from a collaborative process with a Canadian sex worker rights organization called Stella, l'amie de Maimie, where we reflect on the use of and potential for digital technologies in service delivery. We analyze the Bad Client and Aggressor List - a reporting tool co-produced by sex workers in the community and Stella staff to reduce violence against sex workers. We analyze its current and potential future formats as an artefact for communication, in a context of sex work criminalization and the exclusion of sex workers from traditional routes for reporting violence and accessing governmental systems for justice. This paper addresses a novel aspect of HCI research that relates to digital technologies and social justice. Reflecting on the Bad Client and Aggressor List, we discuss how technologies can interact with justice-oriented service delivery and develop three implications for design.

Sex workers' rights are human rights, and as such are an issue inherently based in social, criminal, and political justice debates. As HCI continues to move towards feminist and social justice oriented research and design approaches, we argue that we need to take into consideration the difficulties faced by sex workers; and explore how technology can and does mediate social justice outcomes for them. We contribute directly to this challenge by providing an empirical account of a charity whose work is built on the underlying move towards social and criminal justice for sex workers in the UK. Through ethnographic fieldwork, meetings, interviews, surveys, and creative workshops we describe the different points of view associated with the charity from a variety of stakeholders. We discuss their service provision and the ways in which HCI is uniquely positioned to be able respond to the needs of and to support sex work support services.