Storm of Cryptocurrency

There is a big storm of cryptocurrencies all over the world and everyone is thinking, working and trying to invest on cryptocurrency.
I am still very coinscious about it as I have observed the Bitcoin prices fluctuations which made me reluctant to think and invest about cryptocurrency.

Why is it making me confuse?
Because everyone can create and float cryptocurrency in the market who has skills to work and has investment to build data center.
Every country has reserves in the shape of gold, bonds etc. which help to measure the worth of currency of every country but in cryptocurrency, how anyone can estimate the worth of the currency and what are the measures which can help to prevent it to be used in illegal activities which may be create problems for investors or bearer of this currency.

I hope that I'll find the answer of my concerns so I could be able to work and invest in cryptocurrency.