The unreflected promotion of diversity as a value in social interactions -- including technology-mediated ones -- risks emphasizing the benefits of inclusion at the cost of not recognizing the potential harm from failing to protect stigmatized or marginalized individuals. Adopting the stance that technology is not value-neutral, we attempt to answer the question of how technology-mediated social platforms could accommodate \emph{diversity by design}, by balancing the often competing values of protection and inclusion. This short paper presents our research agenda as well as initial analysis and outcomes. Building on approaches from scenario planning and the methodology of Value Sensitive Design, we identify ethical principles and arguments on how to curate diversity, which we seek to operationalize through formal argumentation.