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
it could be happen because bitcoin are really powerfull about what putin said, because the character are really anonymous.