Sure crypto can be dangerous as you might think you can not be tracked down but in reality anybody can be. Just ask the u.s presidential candidates of this years election. 
For me is not dagerous but very profitable, after as president it make more popular for cyptocurrencies again.When we say dangerous it is some kind of a thing that can put you in harm. And do you think that way guys? I don't even think that crypto currencies are dangerous, they may be risky but safe. And crypto's anonymity is not making it dangerous too, maybe if you are just involved in an illegal activity using crypto then maybe that is considered dangerous.
Yes. It is the one that is using it which makes it dangerous. I knife wont hurt anyone if no one will get a hold of it.
Still we cant stop those who use it for illegal activities. Hell we dont even know where the transactions are.