Some form of marijuana is legal in more than half the states, but cannabis businesses -- medical and recreational -- are still running into a cash problem.
Since the drug is illegal under federal law, any bank that handles marijuana money can be charged with money laundering, which forces the industry to deal with large amounts of cash, making them targets for violent crime.
To alleviate the problem, the notion of creating a state-run public bank to handle cannabis business accounts has been floated in several states, including California, Colorado, Michigan, New Jersey and Washington.