From Forensics to Ecosystems: Rethinking Watermarks for Generative AI Oversight

The arrival of generative AI as a cheap, widely accessible commercial service, and the tidal wave of AI-generated synthetic content it has unleashed, have provoked deep epistemic and social anxieties and raised difficult governance questions that policymakers are struggling to address. One approach that has attracted both enthusiasm from regulators and skepticism from researchers is digital watermarking. Signals embedded in a synthetically-generated piece of content indicating that it was AI-generated---possibly even identifying the specific systems that generated it---appear to offer a path toward mitigating risks of genAI that avoids the downsides of more interventionist strategies. But critics warn that watermarks may prove technically brittle, epistemically ambiguous, and politically ineffectual tools. In this paper, we explore the challenges and opportunities of using digital watermarking for AI governance, paying special attention to the specific problem of watermarking AI-generated text. We argue that such critiques often treat the problem of identifying synthetic content as an isolated forensic question. Instead, we propose reconceptualizing digital watermarks as tools for understanding the impacts of synthetic content on media ecosystems, rather than reliably identifying individual pieces of synthetic content. Such an ``ecosystems approach'' more effectively utilizes the features of watermarks. And while this approach raises its own governance challenges, we argue that they are more tractable than the challenges of using watermarks for digital forensics.