http://www.npr.org/blogs/money/2012/12/04/166514067/episode-...
and I remember hearing another Planet Money podcast on bitcoin around the same time:
http://www.npr.org/blogs/money/2011/08/24/138673630/what-is-...
and thinking "why don't the marijuana growers just store their money in bitcoin?" Of course volatility is a big issue, but that can go both ways. Marijuana dealers saving profits in bitcoin in 2012 and before would have made even more in appreciation. Dealers doing so from 2014 would have lost some of their profits (in dollar terms)