Why did China outlaw cryptocurrencies and will others follow it?

The recent announcement by China, the major superpower and one of the most populated country on planet earth, to outlaw the ICOs has definitely braked the skyrocketing boom of cryptocurrencies . This country considers cryptocurrency as an unauthorized activity and presumes that they can lead to financial crimes and frauds. Although they can be right to some extent but in an age where trust is very fragile yet the most used thing on internet, it should have given its people the liberty to choose.
China also fears the crash in its financial growth as the country is very vulnerable to scams.