Blockchain technology is on a collision course with EU privacy law
The bloc’s General Data Protection law, which will come into effect in a few months’ time, says people must be able to demand that their personal data is rectified or deleted under many circumstances. A blockchain is essentially a growing, shared record of past activity that’s distributed across many computers, and the whole point is that this chain of transactions (or other fragments of information) is in practice unchangeable – this is what ensures the reliability of the information stored in the blockchain.
Source: iapp.org