A key feature is the ability to devaluate banknotes that may have been stolen from a DICE user or which are illegally circulating.
I just wonder how they are going to effectively keep track considering the number of notes in circulation. The next thing you know, some of the banknotes that you are holding becomes invalidated because you happen to exchange it with a person who steals it from someone else. I'm not trying to imply that it's all entirely bad, but definitely some of these potential issues need to be addressed and sorted out.