Here is the European Banking Authority on the risks of Bitcoin. (The European Banking Authority (EBA) is a regulatory agency of the European Union.)

The report is titled EBA Opinion on ‘virtual currencies’. It says:

While there are some potential benefits of VCs, for example, reduced transaction costs, faster transaction speed and financial inclusion, these benefits are less relevant in the European Union, due to the existing and pending EU regulations and directives that are explicitly aimed at faster transactions speeds and costs and at increasing financial inclusion.

The risks, by contrast, are manifold. More than 70 risks were identified across several categories, including risks to users; risks to non-user market participants; risks to financial integrity, such as money laundering and other financial crime; risks to existing payment systems in conventional FCs, and risks to regulatory authorities.

And:

Approximately 70 risks can be identified as arising from VCs. Some of these are similar, if not identical, to risks arising from conventional financial services or products, such as payment services or investment products, while others are specific to VCs. In the following, the risks are separated into risks to users, (indicated by the prefix A); risks to other market participants, (B); risks to financial integrity, (C); risks to payment systems in FCs, (D); and risks to regulators, (E). Where useful, a risk category may be further divided into sub categories

It’s a 46-page report, the PDF is here. It sounds like a bit of a hatchet job on VCs in my brief post here, but the report is a lot more detailed and is worth checking out if your that way inclined.