I avoid doing business with some I know, because you tend to trust them too much and that is a very easy way for them to scam you or sell something that is stolen to you.
So what's your priority option, doing business with random guys? I think this is the opposite of what most people do. Dealing with people you know isn't about trust; you simply have a greater chance of recovering your losses because you can identify them better.
Involving in business both with random guys and those we know has different scenarios. Why because there are some certain business we will loved to do with those closer to us and vice versa same goes for other people we do not know and we will still make business with them.
In aspect of buying crypto currency or digital currency is better to stay away from unknown individuals and not to do that business with them, we rather take ourselves to the exchanges and get our deal done through p2p or any other means because making business with unknown users outside exchanges comes with a lot of risk so let avoid it.
Risk of being apprehend, risk of getting involved with the local securities just as the OP mentioned and other risks. So much risks comes along with it so it advisable to even stay away from the closer ones also and get our crypto business done in exchanges and most importantly not only digital currency other things also.