LONDON (AP) — Bank of England Governor Mark Carney has launched a withering attack on cryptocurrencies, such as Bitcoin.

In a speech Friday to the Scottish Economics conference in Edinburgh, Carney laid into the "global speculative mania" that has fueled cryptocurrencies and said they should be held to the "same standards as the rest of the financial system."

Bitcoin is the most popular virtual currency in the world, but has been hugely volatile. Carney said cryptocurrencies, which are not tied to a bank or government and allows users to spend money anonymously, in part have been "reliant ... on finding the greater fool."

He listed a series of concerns including money laundering, terrorism financing and tax evasion.

Even so, Carney said "crypto-assets do not appear to pose material risks to financial stability."