(De)gradation of Personal Data, Soft Proportionality and Identification Details journal article Pierre Notermans European Data Protection Law Review, Volume 7 (2021), Issue 1, Page 134 - 139 Breyer v Germany, Application number 50001/12, Judgment of European Court of Human Rights of 30 January 2020 Obligation to identify oneself when acquiring a mobile telephone card. Storage of ID details. Necessity in a democratic society. No violation of Article 8 ECHR.