What if our government add tax whenever we transact fiat-crypto and vice versa, and the fund will be used for our protection(ICO,Scams,Phishings), for example the government will make a group or sector that focuses on crypto environtment. what do you think?
That's a bad idea, society should always aim to have as few taxes as possible. The first reason is corruption and bureaucratic inefficiency - often times when governments try to solve some problems, they fail and waste money in the process. The second reason is that it's just unfair for those who are willing to take risks and confident in their own judgement in crypto sphere - they would be paying a tax for a service that they don't need.