State Sen. Chris Romer, a Denver Democrat who sponsored the new dispensary rules at the legislature this year, said if dispensaries have to conduct all their transactions in cash, it will make it harder to track their activity. That, Romer feared, could undermine new regulations requiring detailed accounting by dispensaries in the hopes of bringing more transparency to the industry.

"It would be bad for our compliance regime if they had to do 100 percent cash," Romer said.

If dispensaries are considered legitimate enough by the state that they are required to obtain business and sales tax licenses and pay taxes, why aren't they legitimate enough to have a bank account?

It seems to me that if a bank's customer can show proof of a sales tax license number and federal tax employer number, that should be sufficient. If it also shows proof of paying withholding, unemployment taxes, etc., that should be definitive.

Most banks have a little booklet with rules for opening accounts that states they can refuse to open an account for any reason. Nor do they have to provide a reason when they deny someone an account.

The feds need to get moving on passing one of the bills that have been introduced the past several legislative sessions that clearly exempts state-authorized marijuana businesses from criminal liability.

Rep. Jared Polis has signed on to three reform bills and written Attorney General Eric Holder seeking clarification of the feds' position.

For example, H.R. 3939, the Truth in Trials Act, introduced in October, 2009 by Rep. Sam Farr, was referred to the House Energy and Commerce Committee where it's seen no action. It would amend 18 U.S.C. Section 3436 to provide an affirmative defense for the medical use of marijuana in accordance with the laws of the various States.

Someone needs to get these bills moving, or the dispensaries will be forced to become cash-only, which will make it harder for states to judge compliance with tax obligations. The tax revenue is sorely needed. At a minimum, the feds need to issue new banking regulations specifically exempting such businesses or require banks to show a legitimate reason for rejecting accounts.