It's time for big banks to do something about their image problems. Like stop misbehaving.

Wells Fargo forecloses on the home of a couple who lost their fortune to Bernard Madoff’s Ponzi scheme and a bank executive is then caught living and partying in the empty Malibu mansion? Come on.

The bank has billions of dollars and an inarguably large and complex public relations operation. But neither its billions nor its army of flaks can get public opinion to overlook the simple fact that at least one prominent executive at Wells is behaving deplorably. The L.A. Times report about the Malibu house this weekend leads to only one conclusion: The best P.R. move right now would be free. It would be to make sure everyone in the company has gotten the message to shape up.

Bank of America isn’t looking much better today after a federal judge ruled that its no-fault settlement with the Securities and Exchange Commission in which BofA agreed to pay $33 million to clear up allegations that it misled shareholders during its acquisition of Merrill Lynch was unacceptable. Judge Jed Rakoff “focused much of his criticism on the fact that the fine in the case would be paid by the bank’s shareholders, who were the ones that were supposed to have been injured by the lack of disclosure,” a New York Times story says.

Hmm, using shareholder funds to the apparently egregious falsehoods surrounding BofA’s payout of $3.6 billion in bonuses to Merrill employees might not be such a good idea. Why did it take a judge to figure that out?

Opponents of stricter regulation are clamoring for the freedom to let markets take care of themselves. Capitalism is supposed to be guided by rational thought: What’s good for the customers is good for the business. Competitive forces, they say, keep companies’ behavior in line. Those people ought to take a crack at explaining the moves Wells and BofA executives have made.