After 1899, newspapers frequently reported on dum-dum bullets and demonised those who utilised them. Belligerents also mobilised references to alleged enemy breaches of the law in their public diplomacy and propaganda campaigns. Such allegations were particularly prominent during the Russo-Japanese War of 1904–1905 and the First World War. However, the chapter also shows that the term ‘dum-dum’ very quickly came to be utilised as a short-hand reference to identify other moments of transgressive gun violence. Across the twentieth century, a reference to a dum-dum bullet functioned as a marker to explain the normative stakes in time of colonial, state and interpersonal violence as well as to identify a perpetrator as a transgressor. Even after the enormous destruction of the First World War made a mockery of the law of war, dum-dum references proliferated. They continue to do so today. This chapter explains the extra-legal and political contours of these mediated references and argues that dum-dum allegations both enabled and hid a world of enormous violence.