With marijuana now legal — at least for medical purposes — in more than half the states, a small but growing number of federally insured banks have allowed pot retailers and other legitimate marijuana-related businesses to open accounts. Still, some 97% of U.S. banks won’t work with these companies over concerns about the regulatory ramifications, which is why a number of U.S. senators are asking the Treasury Department’s financial crimes division to help the marijuana industry — particularly those businesses that service the industry — move away from being purely cash operations. [More]