Google’s Top Differential Privacy Scientist Challenges EU’s Anonymization Method for Data Sharing
May 6, 2026 – 8:38 am
Sergei Vassilvitskii, a distinguished scientist at Google since 2012 and a highly-cited expert in differential privacy, has raised concerns about the European Commission’s proposed anonymization scheme for forced search data sharing. In written comments to Reuters, Vassilvitskii stated that the method can be reversed in just 120 minutes, or two hours.
There is a recurring theme in EU regulatory disputes involving US tech companies: they argue in defense of user welfare, only to be dismissed by regulators as making self-serving privacy claims. However, this time, Vassilvitskii’s argument carries significant weight.
The EU’s Proposal and the Issue at Hand:
This debate centers around the Digital Markets Act (DMA), specifically against Google under Article 6(11). The Commission seeks to mandate anonymized sharing of ranking, query, click, and view data from Google’s search engine to third-party rivals on FRAND terms.
The deadline for Google to comply is July 27, 2026, with potential fines reaching 10% of the company’s global annual revenue if it fails to meet this requirement.
Unusual Remedy:
What makes this case unique is that the proposed remedy—forcing search data sharing—itself raises significant privacy concerns. Organizations like the Information Technology and Innovation Foundation have highlighted the potential expansion of user-search data exploitation surfaces, a concern not typically associated with standard DMA remedies.
Vassilvitskii’s Evidence:
His assertion that the anonymization method can be reversed in two hours is supported by technical literature and his team’s demonstrated capabilities. This raises serious questions about the EU’s proposed approach to protecting user privacy.