Government fears bitcoin since bitcoin is the first decentralize currency. Which means it is a tax free currency. Government cannot hold it or even stop it. Even the government tries to ban bitcoin, many people will surely try another ways to access and mine bitcoin. It is in the internet. There are many ways to bypass it. Thats why government cannot do a thing to stop it thats why they fear it. They fear that bitcoin can dominate the currency and no more taxes coming to them.