French CNIL Rules Google Analytics Violates GDPR

Background

On February 10, 2022, the French Data Protection Authority (Commission Nationale de l'Informatique et des Libertés, or CNIL) ruled that the transfer of personal data to the United States through Google Analytics violates the General Data Protection Regulation (GDPR). This decision followed a similar ruling by the Austrian Data Protection Authority a month earlier and was based on one of the 101 model complaints filed by noyb, the European privacy advocacy group founded by Max Schrems.

The CNIL's Decision and Reasoning

The CNIL's investigation centered on a website operating in France that used Google Analytics for audience measurement. The authority's analysis determined that:

1. Personal Data Transfer: Data collected through Google Analytics (including unique identifiers, IP addresses, and browser parameters) constitutes personal data under GDPR definitions.

2. Inadequate Protection Measures: The additional measures Google implemented to protect data transfers (including encryption) were insufficient because Google LLC could still access data in clear text when necessary for system maintenance and security.

3. US Surveillance Concerns: As a US-based provider subject to US surveillance laws such as FISA 702, Google could potentially be compelled to disclose EU user data to US intelligence services without adequate redress for EU citizens.

4. Violation of GDPR Chapter V: The transfers did not meet the requirements for lawful data transfers under Article 44 of the GDPR, as reiterated in the Schrems II judgment from July 2020.

Unlike the Austrian case, the CNIL specifically addressed claims about IP address anonymization, concluding that even with this feature enabled, the remaining data still constituted personal data that could be used for user identification when combined with other information.

Compliance Requirements and Timeframe

The CNIL imposed strict requirements on the website operator:

1. One-Month Compliance Deadline: The organization was given just one month to comply with the GDPR, with the primary recommended solution being to cease using Google Analytics entirely or switch to an alternative tool that does not transfer data outside the EU.

2. Broader Warning: The CNIL made it clear that this decision applies to all French organizations using similar services that transfer data to the United States without adequate safeguards.

3. Coordination with EU Authorities: The CNIL emphasized that this decision was made in cooperation with other European data protection authorities, indicating a unified approach across the EU.

CNIL's Specific Recommendations

The CNIL's decision included noteworthy recommendations for organizations seeking to maintain analytics capabilities while ensuring GDPR compliance:

1. Anonymous Statistical Data: The CNIL suggested that audience measurement tools should be configured to produce only anonymous statistical data, which could potentially exempt them from consent requirements.

2. Local EU Processing: The authority recommended using analytics tools that process all data within the EU jurisdiction, eliminating cross-border transfer concerns entirely.

3. Pseudonymization and Minimization: The CNIL emphasized the importance of proper data pseudonymization techniques and data minimization principles when implementing analytics solutions.

Server-Side Tracking Solutions for CNIL Compliance

To address the specific concerns raised by the CNIL decision, server-side tracking with EU-based infrastructure offers several key advantages:

1. EU-Exclusive Data Processing Chain:

   • Deploy server-side tracking containers exclusively on EU-based servers
   • Create data processing pipelines that maintain data within EU jurisdictional boundaries
   • Implement technical barriers that prevent data from being transferred outside the European Economic Area

2. True Anonymization Techniques:

   • Apply irreversible anonymization at the data collection layer before any processing
   • Implement differential privacy techniques to add statistical noise to data
   • Create aggregate-only metrics that cannot be traced back to individual users

3. Consent-Based Processing Framework:

   • Build a server-side consent verification system that validates consent prior to any data collection
   • Implement purpose limitation at the server level to ensure data is only used for consented purposes
   • Create automatic data purging systems that remove data when consent expires or is withdrawn

4. Transparency and Documentation:

   • Maintain comprehensive records of processing activities to demonstrate compliance
   • Implement continuous monitoring of data flows to prevent inadvertent transfers
   • Create technical safeguards that can be audited by data protection authorities

Technical Implementation Guidelines

Organizations seeking to implement CNIL-compliant analytics should consider these specific approaches:

1. EU-Only Analytics Architecture:

   • Deploy self-hosted analytics platforms on dedicated EU-based infrastructure
   • Implement server-side GTM or similar containers on EU servers to process data before sending to analytics platforms
   • Create secure, encrypted connections between servers within the EU only

2. Advanced Anonymization Pipeline:

   • Implement IP address hashing at the edge, before any processing occurs
   • Replace persistent identifiers with rotating session-only tokens
   • Truncate or remove any geolocation data to prevent re-identification
   • Apply k-anonymity principles to ensure data sets cannot be used to identify individuals

3. Contextual Analytics Alternative:

   • Focus on content and page-level analytics rather than user-centric tracking
   • Implement cookie-less measurement techniques that rely on aggregate patterns
   • Use server-side session management that doesn't require persistent identifiers

Conclusion

The CNIL's decision represents a significant development in the enforcement of GDPR requirements following the Schrems II judgment. By aligning with the Austrian decision and coordinating with other EU data protection authorities, the CNIL has reinforced that the use of US-based analytics tools without sufficient safeguards is no longer acceptable under EU data protection law.

For organizations operating in France and across the EU, implementing server-side tracking with EU-hosted infrastructure and proper anonymization techniques is not just a best practice—it's becoming a regulatory necessity. As the CNIL's decision demonstrates, simply relying on standard contractual clauses or implementing basic measures like IP anonymization is insufficient to meet GDPR requirements for international data transfers.

By adopting a comprehensive server-side tracking approach with strict EU data residency and advanced anonymization techniques, organizations can maintain valuable analytics capabilities while fully complying with the GDPR and the specific guidelines issued by the CNIL, setting a foundation for sustainable, privacy-respecting analytics practices.