Ethereum Co-Founder Buterin Warns World ID Could Threaten Online Pseudonymity

Vitalik Buterin, the co-founder of Ethereum, has raised significant concerns about the potential impact of World ID on online pseudonymity. Buterin's primary worry is that the project's "one ID per person" model, despite utilizing zero-knowledge proofs (ZKPs) to enhance privacy, could inadvertently link all user activities to a single, trackable profile. This centralization of identity control poses serious risks, particularly in authoritarian regimes or under flawed biometric verification systems, where it could enable coercion and surveillance.

Buterin's concerns are not limited to World ID but extend to other digital identity systems that employ ZK proofs. He argues that even with these privacy-enhancing technologies, the practical level of pseudonymity could be lower than the current status quo. This is because users might be forced to consolidate their online presence into a single, identifiable profile, eliminating the option to maintain separate pseudonymous identities. In many real-world scenarios, people use multiple accounts to safeguard their privacy, and forcing users to consolidate into one ID removes that choice.

The World ID project, previously known as Worldcoin, claims over 13 million verified users. Created by Tools for Humanity and co-founded by Sam Altman and CEO Alex Blania, World uses biometric data collected through iris scans to confirm a person’s identity. Upon verification, users receive a World ID and are rewarded with WLD tokens. World uses ZKPs to protect user data, proving that someone is human without revealing their personal information. Buterin acknowledged the increasing relevance of digital identity solutions across the globe.

Buterin highlighted the risks of a single global ID system. He explained that if every digital action must link to one permanent ID, it could eliminate the flexibility offered by pseudonymity. This could prevent users from managing multiple online accounts or separating activities across platforms. In his analysis, Buterin warned that even with ZK protection, widespread adoption of one-per-person IDs might result in stricter user tracking. Social platforms could adopt rigid ID models, limiting users to one account and reducing anonymity. Buterin indicated that current platforms like Google still allow users to hold several accounts, offering more online flexibility.

Buterin proposed a decentralized, pluralistic identity model to address these privacy concerns. This concept promotes systems with no single authority controlling identity issuance, instead suggesting a distributed model with multiple ID sources such as government documents, social platforms, and community networks. This approach increases error tolerance and enhances inclusivity, allowing stateless individuals or those without official IDs to still participate. Systems like Circles already explore this model using social graphs for verification.

Buterin emphasized that a pluralistic system balances privacy and usability better than a one-size-fits-all model. It resists monopolies while supporting diverse communities. He also highlighted the importance of anti-Sybil measures to prevent fake or duplicate identities, rejecting wealth-based identity proof as unfair. Instead, he recommended quadratic scaling, where creating multiple IDs becomes increasingly costly, balancing accessibility and abuse prevention.

The pluralistic identity idea aims to preserve open participation without sacrificing privacy or fairness. It also reduces the influence of dominant identity providers. Buterin envisions a digital identity ecosystem where users can choose from multiple verification options, ensuring both security and flexibility. The pluralistic identity framework emphasizes personal control, privacy, and global inclusion, arguing that only such a system can maintain freedom and prevent coercion in the digital world. The next challenge is building infrastructure that puts these principles into practice.