There was already much discussion about reviving 1930’s-style regulation of banks before Obama’s dramatic and combative announcement on January 21. The proposals for what is now called the “Volcker rule,” which would ban proprietary trading and prevent banks from “owning, investing in, or sponsoring” hedge funds or private equity funds, is an updated version of the Glass-Steagall Act, the law enacted in the United States in 1933 to separate investment banking from commercial banking.