The report that legal marijuana sales have topped $5.4 billion in 2015, and is expected to reach $6.7 billion this year, has many pot prohibitionists questioning their allegiance to what amounts to a losing battle. It also has cash-flushed pot businesses scrambling to find a place to put their literal piles of cash.

The problem is that while states like Colorado, Oregon, and others have given the green light on marijuana legalization, the federal government still has it as a Schedule One drug—right next to heroin and LSD. This means that federally insured banks can’t open accounts for local cannabis companies without serious risk of penalties.

“Banks face a number of risks if they choose to serve the industry, up to and including closure of their institutions,” Amanda Averch, director of communications for the Colorado Bankers Association, told the LA Times in December. “Regulators can impose civil money penalties, cease-and-desist orders, fines, and can ban bankers from their careers for life.”

Thus the multibillion-dollar industry runs as it did when it was wholly an underground undertaking—on cash. Bags and bags of cash. Which presents another problem—security. A task that is provided by armed guards, who shuttle not just the quasi-legal products around, but the money, too.

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