“I think most of us just don’t recognize the false picture of the company that is being painted,” Zuckerberg wrote in a Facebook post on Tuesday night. “I’m proud of everything we do to keep building the best social products in the world.”

In her testimony, Haugen said that Facebook maximizes profits at the expense of its users. She said that Facebook has targeted younger and younger users even after internal research showed that its platform Instagram is addictive and harmful to teens. She also said that the firm has little willingness or means to combat issues like the spread of misinformation on Facebook and the company’s other platforms like Instagram and WhatsApp, a problem that is even worse outside the U.S. where Facebook has less oversight of its content.

“Yesterday we saw Facebook taken off the Internet… I know that for more than five hours, Facebook wasn’t used to deepen divides, destabilize democracies, and make young girls and women feel bad about their bodies,” Haugen said, nodding to a five-hour long global Facebook outage on Monday.

Zuckerberg dismissed Haugen’s accusations in their entirety.

“At the heart of these accusations is this idea that we prioritize profit over safety and well-being. That’s just not true,” Zuckerberg wrote in a Facebook post on Tuesday night. “I don’t know any tech company that sets out to build products that make people angry or depressed. The moral, business and product incentives all point in the opposite direction.”

Still, Haugen’s testimony struck a bipartisan nerve in D.C.

“It is clear that Facebook prioritizes profit over the well being of children and all users,” Sen. Marsha Blackburn, a Republican from Tennessee, said at the hearing.

“I think the time has come for action. And I think you are the catalyst for that action,” Sen. Amy Klobuchar, a Democrat from Minnesota, said on Tuesday, referring to Haugen.

Zuckerberg acknowledged that he has found it “difficult to read” recent coverage about Facebook, but admitted no fault in his company’s actions or any willingness to change. He also shot back at Haugen’s accusations that Facebook knows its products are detrimental for children but is marketing them to kids anyway.

“I’m particularly focused on the questions raised about our work with kids,” Zuckerberg wrote. “It is incredibly sad to think of a young person in a moment of distress who, instead of being comforted, has their experience made worse. We have worked for years on industry-leading efforts to help people in these moments and I’m proud of the work we’ve done.”

Zuckerberg also called Monday’s Facebook blackout the “worst outage” the firm has had in years, but said it was a reminder how much Facebook’s platforms matter to users. “The deeper concern with an outage like this isn’t how many people switch to competitive services or how much money we lose, but what it means for the people who rely on our services to communicate with loved ones, run their businesses, or support their communities,” he wrote.

Zuckerberg did not specifically name Haugen in his post. But on Tuesday other Facebook representatives argued that she was a low-level employee who had little knowledge of Facebook’s internal affairs or business practices.

Lena Pietsch, a Facebook spokeswoman, said Tuesday that Haugen only worked at Facebook for less than two years, never attended a meeting with C-suite executives, and did not have a direct report at the company. “[Haugen] testified more than six times to not working on the subject matter in question,” Pietsch said.

Congress, at least, took her accusations seriously.

“Mark Zuckerberg may be one of the richest people in the history of the world. But today Frances Haugen showed that one person can stand up to that kind of power and make a difference.” Sen. Richard Blumenthal (D–Conn.) said Tuesday.

Haugen, who released a trove of internal documents to the Wall Street Journal and appeared on CBS’ 60 Minutes on Sunday, called for Facebook to be more transparent.

“As long as Facebook is operating in the shadows and hiding its research from public scrutiny, it is unaccountable,” she said during her testimony.

In his post, Zuckerberg pledged to make more of Facebook’s internal research available to the public. But such limited measures are unlikely to pacify a growing and united opposition in D.C.

“Here’s my message for Mark Zuckerberg: Your time of invading our privacy, promoting toxic content and preying on children and teens is over,” Sen. Ed Markey, (D–Mass.) said Tuesday. “We will not allow your company to harm our children and our families and our democracy any longer.”

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