For historians studying socially and historically marginalised groups, archives of disciplinary institutions often contain a range of valuable sources, some of which are autobiographical in nature. However, when using these intimate sources, researchers must fulfil legal requirements to comply with various norms on privacy protection. This balancing act between giving voice to vulnerable groups and respecting their privacy gives rise to several ethical dilemmas. This article provides a framework to assess the balance between privacy protection and the disclosing of names. It starts with a discussion concerning the methodological implications of anonymisation. It then discusses four issues pertaining to privacy protection when using autobiographical material from institutionalised individuals: (1) Can naming cause harm to living persons? (2) Can naming fight social stigma? (3) Does anonymisation make people invisible? (4) Does naming violate the posthumous privacy of the deceased? I use my own research on autobiographical documents of juvenile delinquents in Belgium (1890-1960) as a case study.