Keeping pot businesses cash-only an open invitation to crime?

WASHINGTON, D.C. -- It's been about three months since the Department of Justice announced they'll stand down on enforcing federal law in well-regulated states where marijuana is legal.

Officials say the next hurdle for recreational marijuana is the enforcement of federal banking laws. Legitimate marijuana businesses in Washington and Colorado will be forced to operate on a cash-only basis.

Representative Denny Heck (D) questioned Treasury Secretary Jack Lew on the subject.

Heck said marijuana is projected to be a $1 billion a year industry in Washington state. He is concerned that such a large amount of money floating around in all cash is a threat to public safety.

"It is, in fact, sir, an open invitation, it's setting out the welcome mat to organized crime and disorganized crime," Heck said. "It's setting out the welcome mat for tax avoidance, it is an open invitation to all sorts of activities which will render us and our communities and our neighborhoods less safe."

Lew said he recognizes the serious challenges that states face when federal and state laws are not consistent.