Bitcoin is not responsible for this.Criminal commit their crime anyhow.Before bitcoin here was crime and it will be if bitcoin don't exist
Yes Bitcoin is really responsible for many criminal activity and due to this reason it is ban in many country. Bitcoin provide uninterrupted and untraceable money transaction facility. Due to this many terrorist organisation use it for their different purposes like kidnapping, murdering child pronography etc 
. Many Anti social people use bitcoin as sources of scam. Bitcoin also provide opportunities to many criminal minded people to fraud people on the Internet. Many Businesses and politician using Bitcoin transaction facility for transfer their black money 