Actually government have power to make bitcoin or cryptocurrency get down, but few moment awhile behind bitcoin and altcoin price get easily recovery back to higher price. I can comparison when China banned bitcoin as transaction in their country and make bitcoin get significant decreasing, without waiting more longer time bitcoin success recovering back to higher price and reach most expensive price before banned by China.
Although government have power crack down cryptocurrency but they can't controlling bitcoin or altcoin price keep going down forever, have dominance by investor hold bitcoin and altcoin assets make difficult for government to crack down.