[Vitalik: Privacy Protection Must Be Full-Stack, Mixnets and Encrypted Payments Are Key Foundations for AI Agents' Privacy] Deep Tide TechFlow News, March 8th, Vitalik posted on the X platform, pointing out that encrypted privacy is crucial to prevent the leakage of access pattern information during API calls. Even when using local AI agents, external observers can still obtain a significant amount of user behavior information by analyzing search engine call records. He believes the first-layer solution is to use mixnets for calls, but this brings the need for anti-DoS attack mechanisms, which in turn leads to pay-per-call models. The default payment methods are often credit cards or stablecoins that do not prioritize privacy, so true privacy protection ultimately still relies on encryption technology. Vitalik also emphasized that privacy protection must be considered from a full-stack perspective, with the local AI agent layer being particularly critical. He drew an analogy to anti-aging research: if there are 10 factors damaging the body, repairing one can extend lifespan by 11%, repairing two extends it by 25%, and repairing three extends it by 42%. Similarly, protective measures against data leakage risks exhibit a compounding effect with superadditive benefits.