Seven years ago, Meta Chief Executive Mark Zuckerberg testified for the first time in Congress. After a two-week boot camp by lawyers, he answered questions at three consecutive Buck-to-Buck hearings in two days of baptism by fire to prepare him.

Zuckerberg, 40, has been practicing more since. He made eight appearances before Congress and testified at least twice in court. He defends his company, previously known as Facebook, on issues such as privacy, child safety, and the spread of disinformation.

As early as Monday, Zuckerberg will once again be in a hot seat. This time, as a marquee witness in a landmark federal committee lawsuit accusing Meta of breaking antitrust laws. Regulators sued the US District Court company in the District of Columbia over the acquisition Instagram And WhatsApp says it used “buying and boring strategies” to maintain its monopoly on social media.

Zuckerberg’s turn as a serial witness has become a powerful symbol of Washington’s growing frustration with the power Silicon Valley holds, spurring attempts to curb the tech industry. Under President Trump, the technology chief is welcoming with the administration in hopes of regulators taking softer hands, but his appointees have shown continued scrutiny.

At Capitol Hill, lawmakers have stepped down as Zuckerberg, accusing him of lying and are personally responsible for various social harms. Legal experts said previous tough questions could help him during the expected seven-hour testimony defending Meta in antitrust law.

“He seems to be more aware of the audience he’s talking about compared to his previous years,” said Adam Sterling, Associate Dean at Stanford Law School. “Whether it’s a deposit, a lawsuit, or in front of the Senate, he can actually create a message to that recipient.”

Meta and the FTC declined to comment.

It’s a far cry from Zuckerberg’s start in his Harvard dorm room 21 years ago. After building “Facebook,” he dropped out of school and moved to Silicon Valley to build a social network. His successes and failures were publicly scrutinized.

In 2021, he renamed his efforts to cut some of the company’s packages to Meta. He recently courted Trump. This month he visited the White House to try and persuade the president and his aides to settle the FTC lawsuit.

Government scrutiny and legal challenges did not inflict permanent damage on the company. Meta’s stock price has more than doubled since Zuckerberg first appeared in Congress.

Zuckerberg is likely to face tougher times in the stands in antitrust trials, legal experts said. Congressional hearings feature spectacular features by lawmakers, each limited to a few minutes. The FTC lawyers plan to bake Mr. Zuckerberg for hours. They also have a chunk of his emails and other communications and will ask him to defend documents that prove his company’s maliciousness.

“Trials are another beast as the other counsels are well prepared, ask better questions and keep focused on their cases,” said Nu Wexler, former policymaker for Meta and principal of Four Corners Public Relations.

In 2017, Zuckerberg testified in Dallas in a trial by video game company Zenimax Media about intellectual property theft claims. He also testified in 2023 during an FTC trial in San Jose, California to block the acquisition of Meta’s Virtual Reality Company.

Now, the FTC is asking Judge James E. Boasberg to convict Meta of antitrust violations, which is “exposed to more in danger,” said Katie Harbus, former public policy director for Meta and chief executive of consulting firm Anchor Change.

For the first half of Meta’s history, Zuckerberg has stepped away from the unscripted public appearance. In 2010, he groped through interviews at a technology conference and struggled to answer privacy questions as sweat beads ran through his face.

Most of his public witness experience came before Congress.

Zuckerberg faced a major backlash from Washington State Senators after the 2016 presidential election. Reports have emerged that Facebook has given political consulting firm Cambridge Analytica access to people’s social networking data without consent.

That led to Zuckerberg’s appearance at a packed hearing in Congress in April 2018. His lawyers guided him to calm down when interrupted and to postpone answering harsh questions.

“My team will be back to you,” he said multiple times during the hearings.

The following year, Zuckerberg was faced with questions from the House Financial Services Committee on the security and security of the plans of a cryptocurrency company called Libra.

Rep. Alexandria Ocasio-Cortez, a New York Democrat, interrupted Zuckerberg about misinformation in political ads. He frowned at times, sometimes he struggled to find the answer.

California’s president Maxine Waters, who was then Democratic chairman of the committee, accused Zuckerberg of leading the company’s fate to users.

“You’re going to step into your competitors, women, people of color, even our democracy,” Waters said.

“I don’t think I’m an ideal messenger for this right now,” replied Zuckerberg. “We certainly have the work to do to build trust.”

Zuckerberg has been better with the next two appearances, said a legal expert and former employee, showing that he will control more Poland and his answers. He and the chiefs of Apple, Amazon, and Google were summoned in 2020 during the pandemic when the House Judiciary Committee was summoned for a hearing on the power of big technology. In 2021, Zuckerberg, who joined the CEOs of Twitter and Google, spoke to a House committee about disinformation.

Last year, Missouri Republican Sen. Josh Hawley requested at a child safety hearing that Zuckerberg would apologize to parents who lost their children due to bullying and other harms accused of refueling Instagram.

“I’m sorry for everything you’ve gone through,” Zuckerberg told parents in attendance. “No one should experience your family suffering.”

Holy said it is important to keep Meta and Zuckerberg accountable.

“This was my whole goal of enforcing a moment of truth,” Holy said in an interview. “But the truth is that he will continue to sail first and do so until there is a real outcome in Congress and in court next week.”