As Facebook Chief Operating Officer Sheryl Sandberg and Twitter CEO Jack Dorsey fielded what were initially barbed questions from lawmakers about nefarious Russian influence in U.S. elections, there was a sense of deja vu.

“If the answer is regulation, let’s have an honest dialogue about what that looks like,” said Sen. Richard Burr (R., N.C.), chairman of the Senate Intelligence Committee.

We’ve come to expect the same back and forth between the earnest if evasive tech executive and the stern if grandstanding politician that we saw Wednesday when they testified before the Senate Intelligence Committee.

But there was something different this time. Here’s what you need to know.

A thaw in Washington’s fight with Big Tech?

This episode of Silicon Valley vs. The Beltway, which has had running installments on Capitol Hill a few times over the past year, featured something different: an apparent thaw. Appreciative senators from both parties applauded the efforts of Facebook (FB) and Twitter (TWTR) for their plans and actions to minimize what Burr called efforts to manipulate social platforms to “foment social discord,” “chaos,” and “turmoil.”

Sen. Mark Warner (D., Va.), a vocal critic who in July circulated a policy paper with 20 options for cracking down on technology giants such as Facebook for the spread of disinformation, protecting consumers’ privacy, and promoting competition in the tech industry, thanked Sandberg for Facebook’s renewed commitment to transparency.

“Without question, positive things are happening,” Burr said. “But clearly this problem’s not going away.”

Shane Green, U.S. CEO of Digi.me—a data-privacy platform that puts members in control of what’s collected, stored, shared, and sold online about them—said the hearings were “not as confrontational” as previous ones because both sides are “getting to know each other better.”

Wall Street wasn’t impressed

If only investors were as chipper as members of the Senate.

Alphabet Chairman John Hennessy talks to The Wall Street Journal about the duty of board members and the best students to come out of Stanford University, where he directs a scholars program.

Admissions by both Sandberg and Dorsey that there are flaws in their social-media platforms requiring significant changes—changes that will ultimately impact the companies’ bottom lines—was heard loudly and clearly on Wall Street.

Shares of Twitter sunk 6% to $32.73. Facebook dropped 2% to $167.18, and Google parent Alphabet (GOOGL) dipped 1% to $1,199.45. (Google was not represented at the nearly three-hour hearing because the committee considered the executive that the company volunteered to send, Chief Legal Officer Kent Walker, not high-ranking enough.)

Dorsey and Sandberg are as different as their companies

The cool, unflappable Dorsey was a particularly effective speaker, even though his blunt honesty probably hurt Twitter’s stock. He repeatedly made it clear he was prepared to take apart and reassemble the company’s business model to get it right.

“We need to question the fundamental incentives that are in our product today,” Dorsey said.

Sandberg, who has worked as an aide to former Treasury Secretary Larry Summers and knows a thing or two about dealing with bureaucrats, was more circumspect. Like Dorsey, she was amenable to new digital tools that would make it easier for consumers to access and control their own data.

Sandberg said Facebook has “always shared information with other companies but we are doing better and can continue to do better. The faster we can collaborate, the faster we share those tips with each other, the stronger our collective defense will be.”

The path to regulation seems inevitable

European regulators and California lawmakers have taken steps to harden laws on privacy and data, and companies like Facebook and Twitter are more receptive to some form of government oversight. Dorsey on Wednesday called for “a more regular cadence of meetings” with government officials.

Tech companies such as Apple (AAPL), Microsoft (MSFT), Snap (SNAP), Amazon.com (AMZN), and others have met twice since late May, at Facebook and Twitter, to collaborate on addressing an issue they have long overlooked or, in some cases, dismissed.

“The threat of regulation has a way of making companies change how they do business,” Megan Stifel, former director of International Cyber Policy in the National Security Council at the White House, told Barron’s. “The senators have seen that social-media companies have put their money where their mouth is, literally.”

The actions were overdue, she acknowledged, but have led to a more placatory dialogue between tech execs and pols.

“The right regulation is more transparency, and user access to data,” said Green, the Digi.me executive. “That’s where consumers win.”

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