What comes straight to mind is embezzling the ill-gotten money, but is this even safe? My other neighbor knows I am into Bitcoin and he learned from me, I guess that's how this other neighbor knew, I told him to go meet the next neighbor but he said he is not ready to teach.
What will you do if something like this is happening around you? Why would a drug dealer want to learn Bitcoin if not for a safer haven for running the business?
My mind isn't settled as I keep thinking different things, what is on your mind readers?
If Bitcoin is legalized in my country, I don't think anything will stop me from teaching anybody about Bitcoin; so far, I will know what such a person wants to learn, which is not a bad thing. So in this case, if my neighbor is a drug dealer and I know about his illegal activity and he also knows that I have an idea about his involvement in crime, I will try and advise him to leave if he understands it, and if he doesn't understand, that is also good, but I know that will never stop me from teaching about Bitcoin. I will not care about what they are willing to use it for because I know the purpose of Bitcoin's creation is a good one. If I decide to have negative feelings about the person gaining the knowledge of Bitcoin, but its purpose is just to invest, I may be getting it wrong, so the best thing for me is to just play my role and teach anyone who is willing to learn about it.