"Social media platforms have become powerful tools to amplify and share narratives. Like many evolving technologies, platforms such as Twitter or Facebook may be used for social good or for ill. Digital vigilantism (whereby social media platforms are used for organised shaming, hounding or doxing of a target deemed by the online community to have transgressed norms) may have real-world consequences. In extreme cases this may result in acts of ‘terrorism’ or other forms of unlawful killing. Yet while digital vigilantism may appropriate traditional law enforcement mechanisms, in some cases it may also try to hold law enforcement to account. Key points: Digital vigilantism, including using video material, is found in Kenya and South Africa, with doxing and hounding observed in conversations about foreigners in South Africa and police brutality in Kenya; in Kenya, digital vigilantism seeks to hold traditional law enforcement mechanisms to account through acts of shaming, usually without usurping their powers; in South Africa, digital vigilantism did at times seems to seek to usurp traditional law enforcement; in both countries, engagement and promotion of new ideas was minimal; key influencers leverage existing networks to amplify their messages, including by using video material – some of it fake – to extend their reach." (Summary)