Bitcoin is a symptom of the internet right? so whoever controls the internet controls bitcoins..
Can the government shut down the internet? Yes they can!
So who controls bitcoin?
Governements controls internet and they can shutdown but they won't , do you imagine the financial losses if the internet just shutdown for 5mn on the whole world ? well it's huge .
Bitcoin is decentralized but governement should be able to ban Bitcoin or block it somehow since it's Peer to peer and they is no way in hell all countries agree to shutdown bitcoin