Cash is great when the people you want to deal with are all in the same room, or at least can easily arrange to be (though governments are quite good at stopping them getting together when it suits them).

You're also subject to control as soon as you try to interact with financial products or "the financial system", even with cash. Try opening a bank account or buying equities without giving a real name and address.

I would like a type of cash that works wherever the other parties happen to be. I'd also like to see that privacy and freedom to transact extend across the full system.