From the Government report:
3.3 Almost all respondents to the call for information commented that digital currencies can offer a degree of anonymity to users, and that this factor could be a driver of criminal activity. Contributions also noted that the use of specific digital currencies, and anonymising services can increase the degree of user anonymity. However, stakeholders diverged in their assessment of the overall significance of the risks here. Some banks and payment scheme companies characterised digital currencies as anonymous and untraceable, but many of the submissions from users, digital currency firms and consultancies challenged this view and termed the technology ‘pseudonymous’ rather than anonymous. They noted that the publically visible ledger (or blockchain) of historical transactions makes digital currency payments less opaque than traditional payment methods, especially cash. Stakeholders saw that this ledger of historical transactions could potentially prove helpful for regulators and law enforcement.