The work analyses the legislative measures which the Party States in the Additional Protocol at the 2003 Convention on Cybercrime are obliged to adopt in order to harmonise the criminal legislation on the dissemination of "racist and xenophobic material" on the Internet, classifying as criminal certain conduct against individuals or groups for reasons of their race, colour, descent, national or ethnic origin or religion, addressing firstly the interpretative issues which its composition brings forward and which were addressed by the Explanatory Report. Next, there is a study of the problems posed by the application of the criteria resulting from the Protocol to that which is termed "hate speech" in social networks: the intentionality of both the conduct and the effects brought about by the dissemination, taking into account the specifities of the social networks; intentional dissemination to the public in relation to the conduct, which is separate from private communications that are unpunishable due to the predetermination of the recipient, with the problems which arise when the recipient is a group of people; and the definition of the racist and xenophobic material which advocates, promotes or incites hatred, discrimination and violence, by reference to the international instruments in which incitement is a key element so that "imminent danger" is incorporated as an additional implicit requirement in accordance with the recognised North American standard. Finally, there is an examination of how some of these criteria in particular, the doctrine of "imminent danger" have been applied in a recent judgement by the European Court of Human Rights in 2018 on Internet hate speech.