All the fuss over who should head the federal government's new Consumer Financial Protection Bureau is a lot more interesting than the details of what the agency is likely to do.

Will the president tap Harvard University law professor Elizabeth Warren, a live wire who the banking industry fears? Will he go with a blander choice?

Will it matter?

Yes, because the agency is up for grabs. It exists today as an empty page ready to be filled in, and the sketchy outline of it should give everybody pause. Given how broadly the law's written, the CFPB, as it's called, is pretty much a blank check for re-regulation of the banking industry. Big Brother would approve. We see trouble afoot.

The CFPB will be housed within the Federal Reserve, but the Fed and related regulatory agencies will have no say in its decisions unless the safety and soundness of the financial system is imperiled. The agency's new director, whether Warren or some technocrat, will be appointed to a five-year term, with no supervisory board and no congressional oversight of budget appropriations. That's a lot of unfettered power and freedom to act.

The mission will be to protect consumers from deception and abuses by the financial services industry. In addition to exercising broad enforcement powers, the agency will set fees and terms of consumer financial products. Anyone who wants the government to "do something" in the aftermath of the economic crisis is going to love this.

Let's say the CFPB decides payday loans are bad. It might very well ban them, in effect, by setting such low fees and generous lending terms that no one could afford to offer the products.

Or the agency may decide that poor people need accounts at mainstream banks. Low fees and generous terms could do the trick.

But of course there's no free lunch, even if the government would like to pretend otherwise. Free checking, for instance, costs banks a lot of money. For years, it has been subsidized in part by the debit-card fees that retailers pay. Debit fees were targeted in this year's legislation, so financial institutions will have to make up their costs some other way. Maybe free checking accounts of the future won't be eligible for teller service, or paper account statements. Maybe banks just won't offer them anymore.

Who doesn't resent overdraft fees, credit-card late fees and just about every other fee that bankers slap on? But if you cut those, something else has to give. Unintended consequences typically follow.

It's easy to understand why so many businesses want nothing to do with the CFPB: Imagine the champagne corks popping in recent months when industry lobbyists succeeded in securing exemptions. Auto dealers got a last-minute reprieve, so Uncle Sam won't be dictating the fees and terms of car loans. Retail merchants, residential real estate brokers, manufactured home retailers, accountants and tax-preparers, state-regulated insurers, commodity traders and charities all got a pass. So did trading and brokerage firms covered by the Securities and Exchange Commission. Lawyers are specifically exempted too.

Who's on the hook? Banks, savings associations, credit unions and the "shadow" banking system of check cashers and payday lenders. That's a nervous bunch these days, and well it should be.