Before turning in the executive restroom key last week, outgoing Federal Reserve Chair Janet Yellen had one final task: bringing the hammer down on Wells Fargo. Responding to a litany of failures at one of America’s largest banks, most notably the issuing of 3.5 million fake accounts to customers without their knowledge, the Fed announced sanctions against Wells, including restricting the bank’s growth and removing four board members.

This is not nearly the punishment that Wells Fargo deserves. (I’ve said for months that the bank doesn’t deserve to be in business anymore.) But compared to what the nation’s banking regulators usually do (or rather, don’t do) when faced with financial malpractice, it’s a pleasant surprise and a small measure of accountability. And it’s directly attributable to one woman: Senator Elizabeth Warren, who pleaded with Yellen for months to punish Wells Fargo. The incident shows that you can’t always measure political leadership and success through a legislative scorecard.

Last summer, as news of Wells Fargo’s continued abuses mounted—from issuing unwanted insurance and home warranty products to clients, to repossessing the cars of servicemembers while they were on active duty—Warren and her staff found that, under a section of the U.S. Code, bank regulators had authority to remove members of the board of directors if they “violated … any law or regulation” or “engaged or participated in any unsafe or unsound practice.” In the era of Trump, there weren’t many regulators with the will to take this on, so Warren focused on Yellen, an Obama-era holdover.

By failing to create risk management practices that would have stopped the fake accounts and other abuses, the holdovers on Wells Fargo’s board violated their obligations, according to Warren. As she put it in a detailed letter to Yellen last June, “The Federal Reserve must hold Board members accountable for their risk-management failures—both to ensure the safety and soundness of one of the country’s biggest banks and to show the rest of the banking industry that poor risk-management practices will not be tolerated.”

Warren followed this up in public testimony, urging that all twelve board members present during the fake accounts scandal be fired. “Fines are not working with these giant financial institutions,” Warren told Yellen, pointing to the series of penalties already assessed on Wells Fargo. “If bank directors who preside over the firing of thousands of employees for creation of millions of fake accounts can keep their jobs, then I think every bank director in this country knows that they are bulletproof and that poses a danger to the rest of us every single day.”