Proving once again that they are tuned closely to the beating pulse of current politics, Senators Bernie Sanders and Elizabeth Warren spoke out last week against the banking industry for continuing to refuse to to do business with legal marijuana organizations.

As it turns out, and as Senator Warren and Sanders pointed out in a letter to the Financial Crimes Enforcement Network, the banking industry has an extensive lists of banned companies and individuals who are not able to open accounts in the U.S., all of whom are connected in some way to the cannabis industry.

“The majority of legal marijuana businesses, and businesses that provide services to them, are all but barred from participating in the financial system,” they wrote. “As a result, many legal businesses are forced to operate in cash, which jeopardizes community safety

Sanders and Warren teamed up with several other progressive senators to demand that the banking industry accommodate these legal companies and their affiliates, just as they would for any other industry.

The major roadblock to most banks is that a national ban against marijuana is still in place, despite state-by-state legalization. This makes banking policy difficult, and leaves the industry wondering if the feds will come after them if they do business with a state’s legal marijuana industry.

Until the drug is decriminalized or another such national statement is made, these difficulties will likely continue.

Watch.