According to
www.bloomberg.com Putin come down hard against bitcoin by calling for more regulations.
The use of cryptocurrencies bears serious risks, which include money laundering, tax evasion and terrorism funding, Putin said at a conference in Sochi.
Source: https:///news/articles/2017-10-10/putin-is-said-to-hold-first-meeting-on-cryptocurrency-rules
We cannot deny that what Putin is saying is not true at all, proponents of bitcoins themselves have said that bitcoins and other cryptocurrencies is the best way to launder money through exchanges, Regulating the exchanges will minimize the use of bitcoins in these activities, in my opinion regulation is good for the cryptocurrency system.