Elizabeth Warren’s distaste for Wall Street defined her tenure as a regulator and her subsequent campaign for the Senate.

So it was no surprise when her inaugural appearance as a Senate Banking Committee member featured a scathing critique of financial risk-taking.

At a hearing on Thursday examining the oversight of the Dodd-Frank Act, Ms. Warren grilled top banking regulators on their response to Wall Street wrongdoing. Ms. Warren, a Democrat from Massachusetts who helped create the Obama administration’s new consumer protection agency, pressed government officials to justify how they police big banks.

“If they can break the law and drag in billions in profits and then turn around and settle paying out of those profits, then they don’t have much incentive to follow the law,” she declared, receiving a smattering of applause from the gallery. “The question I really want to ask is about how tough you are.”

What followed was the Congressional equivalent of a “Ferris Bueller’s Day Off” moment. “Anyone?” she asked, receiving silence in reply.

Thomas Curry, who as comptroller of the currency oversees many of the nation’s largest banks, finally spoke up. “We do not have to bring people to trial,” he explained, “to achieve our supervisory goals.”

His remarks failed to placate Ms. Warren. She then unleashed her bull-doggedness on Elisse B. Walter, chairwoman of the Securities and Exchange Commission. Ms. Walter noted that her agency pushed for “additional authority” to crackdown on Wall Street.

“We truly believe that we have a very vigorous enforcement program,” Ms. Walter said.

But Ms. Warren countered with this: “Can you identify the last time you took the Wall Street banks to trial?” Ms. Walter promised to “get back to you with the specific information,” adding that “we do litigate.”

Despite the acerbic style, there’s reason to think Ms. Warren was actually holding back. As the leader of the Consumer Financial Protection Bureau, she often faced off with Republican critics of the agency, including one episode where she was accused of lying.

She alluded to the dust-ups in her remarks on Thursday.

“I’ve sat where you sat,” she said to the panel of regulators who testified. “It’s harder than it looks.”