What if you had, let's say....5000 Bitcoins in your custody and suddenly someone demanded it as a ransom in exchange for someone very important to you, would you make the exchange?
Well if someone has 5000 bitcoins I am sure he would be damn smarter and will never let anyone know that he has such an amount. I thibk even satoshi hide his indentity for a reason. And obviously if the person is more important to you than all your money you will surely give up all your bits to get the person back.