Some people have become disenchanted with modern bureaucratic forms and modern governments, and in their attempts to imagine an alternative, have joined the sovereign citizen counterpublic, a right-leaning movement comprised of loosely affiliated groups rejecting the validity of national laws that are present in the United States, Australia, Canada, Germany, the United Kingdom, and other countries. These groups focus their energies on legal systems as they resist modern institutions and have developed a shared semiotic ideology about how legal language works and how legal texts should be interpreted. This semiotic ideology hinges upon a particular form of semiotic determinacy; our article unpacks its implications. Sovereign citizens’ ideology is antithetical to how institutionally entrenched actors understand the interplay of semiotic determinacy and indeterminacy in legal contexts, which leads their logics and historical narratives to resonate with conspiracy theories. We conclude by exploring how this counterpublic re-configures older strands of Enlightenment and Protestant Reformation logics as resistance in this neoliberal moment.