While the role of states, corporations, and international organisations in AI governance has been extensively theorised, the role of workers has received comparatively little attention. This chapter looks at the role that workers play in identifying and mitigating harms from AI technologies. There is high consensus in the AI ethics community on the benefits of reducing harms but less consensus on mechanisms for determining or addressing harms. This lack of consensus has resulted in a number of collective actions by workers protesting how harms are identified and addressed in their workplace. Examining the past decade of AI-related worker activism this paper outlines how different types of workers are positioned within a workplace, and the place of collective action.