The rise of large language models (LLMs) poses challenges to the applicability of data protection rules. There is a lot of debate about the question of whether or not LLMs themselves store personal data. Recently, the Hamburg Commissioner for Data Protection and Freedom of Information (Hamburg DPA) published a discussion paper on large language models and personal data and this paper contains three basic theses as follows:
1. The mere storage of an LLM does not constitute processing within the meaning of article 4 (2) GDPR. This is because no personal data is stored in LLMs. Insofar as personal data is processed in an LLM-supported AI system, the processing must comply with the requirements of the GDPR. This applies in particular to the output of such an AI system.
2. Given that no personal data is stored in LLMs, data subject rights as defined in the GDPR cannot relate to the model itself. However, claims for access, erasure or rectification can certainly relate to the input and output of an AI system of the responsible provider or deployer.
3. The training of LLMs using personal data must comply with data protection regulations. Throughout this process, data subject rights must also be upheld. However, potential violations during the LLMs training phase do not affect the lawfulness of using such a model within an AI system.
The above three theses make it clear that according to the Hamburg DPA, no personal data is stored in LLMs. After the release of this discussion paper, some contra and pro arguments were published discussing this statement. Below, I´ll show the arguments regarding the question whether LLMs store personal data or not and I´ll also show why this question can be relevant.