The Wall Street Journal has an editorial endorsing the proposed "Volcker Rule" on the grounds that it would "limit the opportunities for banks to speculate with federally insured deposits," and thus "would once again draw a risk-taking line that was crossed too often in 2008."
I actually agree that if banks are going to participate in federal deposit insurance, the government can impose some conditions on what the banks do with the insured deposits. But it's worth remembering that Lehman Brothers, Bear Stearns, AIG, Morgan Stanley, and Goldman Sachs all had little to no federally insured deposits. If there's a problem that this financial "reform" legislation is intended to fix, it's not clear that speculating with federally insured deposits was in any way central to it. Federally insured deposits are only one of the advantages big banks have; others include the lower-rate borrowing that comes with "too big to fail" and the access to the Federal Reserve.