Which of the following data privacy concerns can be attributed specifically to blockchain technologies?

The core principle of blockchain is immutability, meaning that once data is recorded on the chain, it is extremely difficult to alter or delete. This feature directly conflicts with data privacy regulations like the General Data Protection Regulation (GDPR), which grants individuals the "right to erasure" (or "right to be forgotten"). This makes it a significant challenge for organizations using blockchain to handle personal data to comply with requests for data deletion, a problem specific to the technology's fundamental design.

A. Phishing is a general cybersecurity threat and is not a technique used mainly by or specific to blockchain technologies.
B. This statement is factually incorrect; blockchain transactions are designed to be immutable and resistant to tampering, not easily tampered with.
C. While data privacy regulations apply to blockchain, stating they "overregulate" is subjective and not a direct technical concern inherent to the technology itself.

1. Finck, M. (2018). Blockchain and the General Data Protection Regulation: Can Distributed Ledgers be Squared with European Data Protection Law? European Parliament. Policy Department for Citizens' Rights and Constitutional Affairs. PE 614.199. (See Section 3.3, "The Right to Erasure ('Right to be Forgotten') versus Blockchain Immutability," pp. 22-24, which details the direct conflict between immutability and the right to erasure).

2. University of Cambridge, Centre for Alternative Finance. (2017). Global Blockchain Benchmarking Study. (See Section 4.3, "Legal and Regulatory Considerations," which discusses the challenges posed by data protection laws like GDPR to blockchain systems).

3. Wüst, K., & Gervais, A. (2018). Do you need a Blockchain? In 2018 Crypto Valley Conference on Blockchain Technology (CVCBT) (pp. 45-54). IEEE. (This paper discusses the properties of blockchain, including immutability, which is the source of the data erasure challenge). DOI: 10.1109/CVCBT.2018.00011.