Panic in the market is created by those people who do not want to believe that bitcoin is a very strong coin. With every minor news, they begin to panic. I think that the government has no way to ban bitcoins
Jamie Dimon taken as a recent example. His bashing did not really caused a panic, but his origins are to be considered.
Goverments are overated in a globalized society. Corporations expanded into the scale of countries. There are banks of that size.
A goverment has ruling limits documented by their constitution. Any of the other players of compareable sizes are not limited by something even similar. I think they are the real thread. And those got a lever into politics by lobbying, bribery or other means.
Does the government can block the internet site? Just like in China, facebook was banned. I think the government of a certain country can stop bitcoin, but as a whole it would be impossible. Some country are interested in this new technology which they want to adopt because of faster system of transaction which blockchain can offer. Bitcoin will grow exponentially if other countries will follow.