California’s Treasurer said Tuesday that the state’s best solution for safely collecting taxes on cannabis is a fleet of armored cars. In the new year, California will usher in what is expected to be the largest legal marijuana market in the nation’s history; it’s anticipated to grow to be worth $7 billion a year, as reported by the Associated Press.

As you may know, legal cannabis is, for the most part, a purely cash business. Though medical marijuana is legal in a majority of the country and recreational marijuana is legal in eight states (and D.C.), almost all banks shy away from doing business with the cannabis industry out of fear of engaging with a substance that is still illegal on the federal level.

As you’d imagine, that leaves cannabis producers and distributors more susceptible to robbery than your average legit businesses. And that’s where the program of armored cars would come in. Based on a task force which investigated the problem, State Treasurer Justin Chiang has advised California to hire an armored courier service so that marijuana businesses can pay their bills and taxes without having guns put in their face.

“It is unfair and a public safety risk to require a legal industry to haul duffel bags of cash to pay taxes, employees and utility bills,” Chiang said in a statement. Chiang himself actually doesn’t seem to think that armored cars and armed guards are necessarily the best solution, just the best solution that’s actually attainable.

He said in his statement that he feels the simplest tactic to avoid making “cannabis operators … and the general public vulnerable to violence and organized crime” would be federal legalization.

Since that’s not too likely in the near future, he also suggested a law that would shield financial institutions from being penalized for banking the profits of marijuana producers. That has sort of been tried. In 2015 the Obama era Justice Department put out guidelines to banks which aimed to help them navigate the cannabis business while avoiding federal prosecution.

But most banks felt that was far from a guarantee of immunity and decided to leave weed alone. The Federal Reserve even shut down a credit union set up by the state of Colorado to help cannabis businesses with their banking in 2015.

So, then, maybe the best solution is the decidedly Dark Knight-like idea of cannabis having to become a militarized business.