there are lots of crimes will happen in this world it will not being supported by cryptocurrency at anytime and people will always use cryptocurrency for good use only and the crimes are always happen for normal paper money I strongly believe cryptocurrency has good way of development.
I think there is a dark side of the cryptocurrency as well but this is true for almost everything around. Look at Elizabeth Holms. She founded Theranos and was something that made her a billionaire but then there have been allegations against her and she had to appear in front of courts. So it is all a game of mind. If you use it for the good, it is a blessing. If not, its a curse.