An insight from my first article on Bitcoin circa March 2013 that I had forgotten about. Just how much the ECB was saying at the time that Bitcoin would "challenge" central banks' monopolies:

"Another way to use actions in the market to free yourself and society is to shun the traditional fiat currencies for inflation-proof currencies. Bitcoin, for example, is climbing in value and increasing in popularity for regular transactions.

A European Central Bank report released in Nov. 2012 called Bitcoin a “threat to financial stability,” and warned it could challenge the “monopoly of central banks” around the world as well as “undermine” the legitimacy of nation states."