Crypto owners that are known to the public are getting targeted in France. You can remember the co-founder of French crypto-wallet firm Ledger, David Balland, was also kidnapped with his wife in January from their home in the region of Cher of central France.
This is the reason why we must keep a low profile if we are engaged in cryptocurrency especially if we are successful in our venture. Wicked people who wanted to profit without doing any hardwork are always looking for someone worthy to prey on.
It appears these criminals might see a more direct route to a crypto holder's assets by targeting their family. Here comes the ultimate question, are you willing to pay the price for your loved ones to be free?... Or keep your crypto holdings private and away from the unknown...
In my point of view, our love one's life is more precious than any wealth in this world, so yeah I would do anything to save my family even if it means I have to agree with the demand ransom of the kidnapper. Wealth can be replace if we are smart enough, but our love one's life is only one.
Since the ransom wasn't made known then we should just keep crypto related thing out of this. We either don't know the net worth of this crypto fortunist which the reason for his kidnap maybe based on how notable wealthy personality in his environment afterall before crypto existed kidnapping has been taking place and other values a.rw being demanded for the ransom.
Except the crypto person has been made known in the society and due to his cautiousness not to befall physical victim such as to the kidnappers, member of his family maybe on the target.
But still, I find this fathers kidnapping experience hard to be related with crypto based on the details of the information.
If you read the context of @OP's post, it is the success of the person in his cryptocurrency venture that triggers the kidnapping. Regardless of the method of payment for the release of the victim, it is clear that cryptocurrency investment success is the key factor for the bad event to happen.