## Facts

- Germany enacted the 1983 Census Act to conduct a nationwide, door-to-door census requiring residents to answer detailed questions about personal, occupational, and housing circumstances.
- The Act authorized collection of extensive personal data for statistical purposes and established mechanisms to process and store that data.
- The Act permitted transmission and linkage of census data with other public registers (including comparison with municipal civil registers) for administrative and correction purposes, and allowed transfers for scientific purposes.
- Individuals filed consolidated constitutional complaints, arguing the Act risked creating comprehensive state profiles of persons and violated constitutional protections for personality and dignity.
- The court issued an interim order suspending implementation pending merits review and later decided the complaints after oral hearings.

## Issues

1. Whether extensive census data collection, processing, and statutory authorization for transmission/linkage violate the constitutional protection of personality and human dignity.
2. Whether the constitution includes a right to informational self-determination, and, if so, what statutory requirements (public interest, clarity, proportionality, safeguards) must be met to justify interferences.
3. Whether the Act’s provisions on transferring and matching census data with other registers are constitutionally permissible for non-statistical administrative uses.

## Decision

- The court held that the general right of personality, read together with human dignity, includes a fundamental right to informational self-determination.
- The basic census questionnaire and data-collection framework were not inherently unconstitutional, provided implementation includes adequate organizational and procedural safeguards.
- The provisions authorizing broad transmission, linkage, and register comparisons for administrative purposes were unconstitutional because they enabled uses beyond statistical purposes and created excessive risks of person-specific profiling.
- The provision allowing transfer of census data for scientific purposes was upheld as compatible with constitutional requirements when implemented with appropriate constraints.
- The legislature was required to revise the statutory framework to conform to the right of informational self-determination.

## Legal Principles

- The constitution protects individuals against unlimited collection, storage, use, and sharing of personal data; individuals have authority, in principle, to decide on disclosure and use of their personal data.
- Interferences with informational self-determination require an overriding public interest, a clear and constitutionally adequate statutory basis, and compliance with proportionality (suitability, necessity, and reasonableness).
- Statutes authorizing data processing must include organizational and procedural safeguards (such as access controls, separation of data uses, and limits reducing misuse and re-identification risks).
- Even where data is collected for statistical purposes, compensating limits are required to prevent drift into identifiable, multi-purpose administrative use.

## Conclusion

The court constitutionalized a right to informational self-determination, upheld census data collection for statistics subject to safeguards, and invalidated broad data-transfer and register-linkage provisions that enabled non-statistical administrative reuse inconsistent with clarity, proportionality, and personal-data autonomy.


Volkszählungsurteil (Census Case), 65 BVerfGE 1 (Ger. Fed. Const. Ct. 1983)