It is up to us to improve Bitcoin and get rid from fraudulent and illegal activities involving Bitcoin. We should not support fraudulent and illegal activities, we should not protect criminals or scammers. Bitcoin is very useful but if some criminals will use Bitcoin to purchase a weapon, where possibly people are murdered from, Bitcoin will take damage and we should not support it.
Bitcoin has improved impressively since Silk Road was busted and Bitcoin growing will help Bitcoin to get independent from criminals and scammers.
As a believer in Bitcoin who knows the importance of Bitcoin and what humanity stands to gain with it, it is our sole responsibility to defend and support Bitcoin wherever we find ourselves, people talking about it, be it good or bad about Bitcoin. That's the effort we can really put in place.
For any fraudulent acts and illegal activities, we can't get rid of them because not everyone is a believer in Bitcoin. There are people on earth who have bad intentions about Bitcoin, seeing Bitcoin as a means of carrying out illegal activities and fraudulent acts. We don't know who they are, if we do, the last thing we can do is to report them to the police for their arrest.