From all the possible scenarios only one is believable and it is all of the government of each country decides Bitcoin as a global threat and decide to ban it worldwide where they have the power to do so within the reach of the internet from banning all wallets to blocking ip addresses it is all possible to be done by the government. But it all depends if people in the future will really abuse the anonymity of Bitcoin that it can affect the economy of a country or the prominent use of Bitcoin to enriching criminals.
All governments deciding to go against Bitcoin is very very unlikely. And even if, it would be very hard for them to do this. The only way I can imagine is if they would manipulate people into hating or distrusting Bitcoin, since it's not really possible to stop the Blockchain everywhere.