[Vitalik Buterin: The AI Era Requires Cryptographic Privacy Mechanisms to Protect API Access Patterns] Ethereum co-founder Vitalik Buterin stated that in the context of the growing prevalence of AI agents, cryptographic privacy technologies are crucial for protecting users' API call patterns and behavioral data. He pointed out that even when using local AI agents, if external services can see all search or API call records, they can still infer the activities users are engaged in. Vitalik believes that an initial solution could involve forwarding requests through a mixnet to obscure the source of access. However, service providers may require anti-abuse mechanisms and pay-per-call models to mitigate DoS attacks, and in practice, these payment methods often rely on credit cards or stablecoin systems that lack privacy protection. Therefore, he emphasized the need for cryptographic payment solutions with privacy attributes. He further noted that privacy protection needs to be considered from the **full stack** perspective, with the local AI agent layer being particularly critical. Vitalik likened this to the issue of healthy lifespan: if there are multiple harmful factors, addressing them one by one can yield cumulative benefits; similarly, measures to reduce data leakage risks can produce comparable compounding effects.