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.
Kidnapping has always be there, I don't think anyone should try to attribute the rise or current surge of kidnapping to Crypto-currency. There are instances where banker connive with kidnappers to kidnap clients with huge bank account. I think own Crypto-currency even gives you the opportunity to be more secured and protect yourself by being anonymous.