I still dispute the notion that merchants are going to embrace Darkcoin.
I don't think an IRS or SEC is going to appreciate the beauty of Darkcoins anonymous transactions. Both of which businesses are required to submit to audits on demand. So lets just close that door. Businesses will never embrace Darkcoin. It makes a nice soundbite when marketing the coin to potential investors but that's about it.
So when random guy walks into a cafeteria and purchases a sandwich and pays with cash, you have to investigate where he got that 10 dollar bill?
EDIT: sorry for responding to clear trolling but just in case someone else hasn't thought this through I decided to respond.