Self-sovereign identity (SSI) solutions implemented on the basis of blockchain technology are seen as alternatives to existing digital identification systems, or even as a foundation of standards for the new global infrastructures for identity management systems. It is argued that 'self-sovereignty' in this context can be understood as the concept of individual control over identity relevant private data, capacity to choose where such data is stored, and the ability to provide it to those who need to validate it. It is also argued that while it might be appealing to operationalise the concept of 'self-sovereignty' in a narrow technical sense, depreciation of moral semantics obscures key challenges and long-term repercussions. Closer attention to the normative substance of the 'sovereignty' concept helps to highlight a range of ethical issues pertaining to the changing nature of human identity in the context of ubiquitous private data collection.