How social bots shape the discourse of online activism

Social bots increasingly shape online discourse, influencing how protest movements are perceived and evolve. This paper identifies bots as a major influence in digital protest ecologies, and responds by updating the Discursive Opportunity Structure (DOS) theoretical framework - focusing on its core dimensions of visibility, resonance, and legitimacy. To ground this theoretical development, we apply this revised framework through computer-assisted content analysis of bot activity in two major protests: Black Lives Matter (BLM) and Extinction Rebellion (XR). Rather than treating bots as a monolithic influence, we identify competing bot strategies with distinct discursive impacts. In BLM, supportive bots enhance cultural resonance, while counter-bots target movement legitimacy. In XR, pro-protest bots work to establish legitimacy and participatory visibility, whereas counter-bots strategically manipulate issue salience. These findings show that any serious understanding of contemporary movements must recognise how bot activity shapes discourse - steering public perception, influencing movement trajectories, and impacting protest outcomes.