Well, it is not the problem with Bitcoin but the human involved. There are also cases whereby people buy and sell drugs or involve in any illegal activities using fiat.
But what makes these things worse was the fact tgat if some people do some illegal activities here they will remain anonymous, in any way that they want they will not be put into jail unless they will leave a trace and I think thats one of the biggest anomalies and fraud that Bitcoin is facing right now, in the prevention for the some countries choose to banned Bitcoin.