Yes, nowadays its being used in crime, they buy and sell online and pay by bitcoin. Because its untraceable. So police cant get clue to caught them. I think its dangerous.
You know if thats the case this should be solved early cause this might affect the insights of the people towards Bitcoin ,yes its not the oirpose of the Bitcoin but the fact that Bitcoin allows this to happened will threaten also this platform, this is not a good thing for a newly sprout system like this, dangerous.