But like every other hot real thing, pennystock scams pop up around it. Crypto currency has greased the wheels of illegal internet commerce. Very easy to buy and pay for drugs (mostly), stolen credit cards, firearms online with the combination of anonymous darknets and crypto currency.
This fall started when the largest illegal exchange, alphabay, got busted and shut down a couple weeks ago. Think ebay with hard drug listings. The exchange sets up escrow and arbitration and was doing big millions of dollars of transactions per day. There is a lot of money that is tied up in escrow and in the exchange wallets of the participants. That will go to the governments. But without the biggest exchange, a lot of demand for BTC disappeared.
Chinese are also using it to get money out of the country. Every crackdown tends to result in BTC weakness
I've used BTC for some legal transactions as it is a fairly inexpensive neutral currency for overseas transactions. Paypal was a niche toy at first, but quickly gained traction to be a real payment system. It'll never compete with credit cards, but it is real nevertheless.
coinbase one of the largest LEGAL currency exchanges