The worst case scenario with digital money is that the authorities could simply cancel your money. Laugh, but this has happened in many countries throughout history. A hard line communist regime could allow you an amount of money every week and if you don't spend it you lose it. Start afresh the next week; no saving allowed!
Does it still say on British notes '.....Promise to Pay'?
The difference between digital money and a piece of paper or plastic saying that is what exactly?