Bitcoin is known as to be the biggest cryptocurrency. in some countries it can be used to purchase goods and services and some see cryptocurrency as a threat.
if Bitcoin comes to be number one currency in the world today, can it be hijack by the government?
Technically governments cannot do anything about bitcoins as long as INTERNET stays decentralized. But, governments may impose all kind of regulations on all types of crypto related entities. But, when people get into P2P level of transactions alone then government restrictions will become void. So, there are less possibilities for governments to hijack bitcoins in any means.
The essence of bitcoin itself is a decentralized system. So the point is how a system is able to run on its own without interference from other parties, and that also includes the government. The government may be able to enforce a fairly stringent regulation like in India, but a decentralized system still allows bitcoin to run even without support from other parties