Kidnappers demanding for ransom in cryptocurrency is not a new thing and sadly as mass adoption increases, so will the rate at which it is used by bad actors to perpetrate evil increase. As it is right now, I think it will be for our own good to protect ourselves by keeping our crypto activities discreet and to avoid living a flamboyant lifestyle. As this will not only keep us safe but also help not to put the lives of our loved ones in jeopardy.
You're right this is why we need to keep our investment plans very secret to people except our loved ones because those that happens to be our friends we don't know their intentions, even most of those people who happens to be our loved ones can also do something that you never thought or imagine that such person could do, So we should always learn how to keep our investment plans very secret to people. However, you know sometimes I think we are the cause of our problems. I could remember one very day when I was going through posts on facebook then I saw a screenshot of someone showing his account balance to the world, then I was like.... Does this person actually know what he's doing by sharing his account balance to the world to see how much he has in his account? so at this point if it is someone who has bad intention towards him, what did you think the person will do? This is why we need to be caution on the kind of things we post or talk to avoid implication.