Controversies over genetically engineered organisms (GEOs) illustrate an important role for social movement actors in contemporary battles over risk, power, and governance. In California, anti-genetic engineering (GE) activism has played a substantial role in the development of strict sub-national regulations for biosafety risks from aquatic organisms and food crops that produce pharmaceuticals. Anti-GE activists framed the debate in terms of who takes risks and who benefits from these risky GEOs, enrolling those whose livelihoods would be most severely impacted. While fighting for precautionary politics on the risk terrain, many of the same activists are engaged in broader debates about the future of the food system. They are at once sowing seeds of resistance and hope for food system paradigm shifts. This paper explores two instances of sub-national regulation of GEOs in California—salmon and pharmaceutical rice—and explains the emergence of these precautionary policies, prospects for similar policies elsewhere, and what these engagements mean for broader food system change.