This isn’t a new issue. Most of the blockchain projects I’ve been involved in are contract ledgers which hold company details rather than individuals’ personal information. Even those holding healthcare information have some form of anonymisation built in…:
[…] The university said there are key privacy issues inherent to current blockchain platforms, with a paper from UniSA emerging technologies researcher Dr Kirsten Wahlstrom and Charles Sturt University’s Dr Anwaar Ulhaq and professor Oliver Burmeister saying the exact features that make blockchain such a secure technology also make it a privacy minefield.
This is due to blockchain using details of previous transactions, including participants’ identities and exchange values, to verify future transactions by embedding this information in the data chain, in addition to the viability of the system being dependent on the uneditable nature of each block.
Pointing to the “right to be forgotten” as present currently in laws such as Europe’s General Data Protection Regulation (GDPR), Wahlstrom said the inherent idea of blockchain clashes with such directive.