"Greg Campbell is just about the last person you'd suspect of growing pot in his basement. A few ill-fated experiences in college revealed he was a terrible stoner, and in the years since, he's not given the green stuff another thought. But his attitude changed when medical marijuana was legalized in his home state of Colorado in 2009. It set off a tsunami activity that was viewed by opposing camps as either Nirvana or the Apocalypse. Dispensaries...