Comment by kordless

You can't secure cash under your mattress with a password, for one thing. That makes cash (and paper wallets) venerable to physical attack, even by vermin: http://metro.co.uk/2007/03/27/mouse-eats-cash-machine-makes-...

There is no problem with value changing tomorrow as this is a potential problem with any new payment methodologies. Adoption does not appear magically overnight. The US Dollar is velocity stable due to its wide spread use and being propped up by the equivalent of a bunch of duct tape and bailing wire.