Who are the lawyers representing Elon Musk, OpenAI and Microsoft?

“No one should be allowed to steal a charity,” Mr. Molo said. “To steal a charity is absolutely wrong.”

Mr. Musk, Sam Altman and other A.I. researchers founded OpenAI as a nonprofit in 2015, vowing to freely share its technology with the rest of the world. But Mr. Musk left the start-up in 2018 after a power struggle with Mr. Altman — and before the public launch of ChatGPT in 2022 catapulted OpenAI to commercial success.

Mr. Musk sued OpenAI in 2024, claiming that the nonprofit he funded with his own large donations took advantage of his financial resources. He also argued that OpenAI breached its founding agreement by putting commercial interests over the public good.

OpenAI’s lead counsel, William Savitt, said in his opening remarks that “We’re here because Mr. Musk didn’t get his way at OpenAI.” He said the original OpenAI nonprofit continues to oversee the for-profit company, and was working to redistribute billions of dollars generated by the for-profit operation.

Mr. Musk is asking for more than $150 billion in damages from OpenAI and Microsoft, OpenAI’s primary partner. He is also asking the court to remove Mr. Altman from the start-up’s board and stop a shift the company recently made to operate as a for-profit company.

The trial’s outcome could upend the A.I. landscape. OpenAI, which has emerged as one of the most important tech companies in the world, could be hobbled just as it appears to be heading toward one of the biggest initial public offerings in history. A win for Mr. Musk, who has his own for-profit lab, xAI, would also be a win for OpenAI’s competitors, from industry giants like Google to young companies like Anthropic, as well as international competitors such as China’s DeepSeek.

If Mr. Musk loses, Mr. Altman will likely solidify control of a company that has become synonymous with corporate dysfunction. And OpenAI, which is now valued at about $730 billion, will be free to pursue a data center expansion plan that could cost hundreds of billions of dollars.

(The New York Times has sued OpenAI and Microsoft, claiming copyright infringement of news content related to A.I. systems. The two companies have denied the suit’s claims.)

Here’s what to know:

• High-profile witnesses: Mr. Musk, Mr. Altman and several other key industry figures, including Microsoft’s chief executive, Satya Nadella, and Mira Murati, OpenAI’s former chief technology officer, are slated to testify in the trial.

• Trial logistics: The trial is set to run for about four weeks before a nine-person jury at the federal courthouse in Oakland, Calif. If the jury rules in Mr. Musk’s favor, Judge Yvonne Gonzalez Rogers — who also oversaw a high-profile lawsuit against Apple over its control of the App Store — will decide on monetary damages and other remedies.

• The stakes: Mr. Musk’s suit demands more than $150 billion in damages from OpenAI and Microsoft. In a recent court filing, he amended his complaint to ask that these damages be shared with the OpenAI nonprofit. He also seeks to remove Mr. Altman from the OpenAI board of directors and unwind the shift that OpenAI recently made to a more traditional for-profit company.

• Musk’s posting: At the beginning of the trial, Judge Gonzalez Rogers called Mr. Musk to the bench to discuss whether there should be a gag order preventing him from posting on social media about the trial. “How can we get things done without you making things worse outside the courtroom?” she asked. The judge asked him — and Mr. Altman — to start with a “clean slate” and “keep things to a minimum” on social media. They all agreed.

Steven Molo, of the law firm MoloLamken, is also part of Mr. Musk’s legal team. Mr. Molo, who specializes in business litigation, led the Musk team during jury selection on Monday.

OpenAI’s team is led by William Savitt, a partner with the law firm Wachtell, Lipton, Rosen & Katz. Mr. Savitt represented Twitter, now X, in its legal battle against Mr. Musk when he tried to withdraw from his $44 billion acquisition of the company.

Microsoft, OpenAI’s biggest partner, which is also named in Mr. Musk’s lawsuit, is represented by Russell P. Cohen, a partner with the law firm Dechert who specializes in antitrust. In his suit, Mr. Musk made various antitrust claims against OpenAI and Microsoft.

Those antitrust claims will not be addressed during the first stage of the trial, which is slated to run for about four weeks. Judge Yvonne Gonzalez Rogers, who is overseeing the trial, has indicated that a second stage focused on the antitrust claims may not happen.

And when Bart and Amy Snyder, farmers in Wolcott, Ind., learned that a data center was going to be built 300 yards from their home, they worried it would drain local aquifers and started a campaign to unseat three county officials who had supported it.

Though none of them had been politically active before, they became part of a growing national movement that pits the tech industry and its billionaires against a diverse coalition of parent groups, religious leaders, environmentalists and former Tea Party activists. Politically they range from the populist firebrand Stephen K. Bannon to Bernie Sanders, the progressive senator from Vermont.

The reasons they are pushing back against the technology are as varied as their backgrounds. But they all worry that tech companies are more focused on cashing in on A.I. than how it may affect regular people. They also share a sense that all that money will flow into the hands of Silicon Valley’s ultrawealthy, while the middle and working classes shoulder the costs.

Many of these A.I. critics say they are far from being Luddites just having a bad reaction to new, scary technology. They believe that people in Washington, especially President Trump, are protecting Silicon Valley rather than reeling it in. They want regulation — or at least a debate before A.I. becomes entrenched in American life.

“Given A.I. and robotics are going to impact every man, woman and child in this country, one might think that there’d be a massive debate in the United States Congress: What does it mean? Where do we go? How do we deal with it?” Mr. Sanders said in an interview with The New York Times. “There has been minimal, minimal discussion.”

A White House spokesman, Davis Ingle, said in a statement that “it is the policy of the Trump administration to sustain American A.I. dominance to protect our national security and ensure we remain the world’s leading economy.”

The White House’s policy framework for A.I., which was issued last month, calls on A.I. services to protect children. This year, Mr. Trump also issued a proclamation that said tech companies “must pay for the full cost of the energy and infrastructure needed to build and operate data centers.”

“Scam Altman and Greg Stockman stole a charity,” Mr. Musk posted at one point, using pointed nicknames for Mr. Altman and Greg Brockman, the president of OpenAI. “Greg got tens of billions of stock for himself and Scam got dozens of OpenAI side deals with a piece of the action for himself.”

(The New York Times has sued OpenAI and its partner, Microsoft, accusing them of copyright infringement of news content related to A.I. systems. OpenAI and Microsoft have denied those claims.)

Mr. Musk has long used the platform formerly known as Twitter to shape public opinion around presidential elections, global politics and other issues. In March, he posted on X about another trial, a case in which he had been accused of misleading investors when he bought Twitter in 2022. Mr. Musk tried casting doubts about the case, but a jury eventually found him partly liable for investors’ losses in the deal.

His posts on X are unlikely to affect the jury in his trial against OpenAI, given that jurors are typically instructed to avoid news and social media. But that has rarely stopped Mr. Musk from drumming up conversations on X that reinforce his point of view.

“The main difference between Elon Musk and Sam Altman: Elon Musk actually changes the world for the better and saves lives,” read one post that Mr. Musk reposted on Monday. “Sam Altman? He mostly just takes.”

Some X users on Monday reported seeing a weeks-old post in their timelines featuring a New Yorker article critical of Mr. Altman. X had labeled the post as “boosted” by Mr. Musk’s account, according to some of those users, which suggests the tech billionaire may have promoted the post. Mr. Musk has made a slew of changes to X to favor his interests, including slowing or restricting access to certain news outlets and competing platforms, and banning some reporters.

Mr. Musk and an X representative did not respond to requests for comment. OpenAI did not immediately respond to a request for comment.

On Tuesday, Judge Yvonne Gonzalez Rogers of the U.S. District Court for the Northern District of California, who is presiding over the case, called Mr. Musk to the bench to discuss whether there should be a gag order preventing him from posting to social media about the trial.

“How can we get things done without you making things worse outside the courtroom?” she asked.

After Mr. Musk said he was just responding to things OpenAI had said online, the judge asked him — and Mr. Altman and Mr. Brockman — to start with a “clean slate” and “keep things to a minimum” on social media. They all agreed.

Cade Metz contributed reporting.

But by the time OpenAI’s chatbot was created, Mr. Musk had left the organization after a power struggle with Mr. Altman and others at the lab. He sued OpenAI in 2024, claiming that Mr. Altman took advantage of his financial resources and breached the lab’s founding agreement by putting commercial interests over the public good.

Mr. Musk is asking for more than $150 billion in damages from OpenAI and Microsoft, OpenAI’s primary partner. He is also asking the court to remove Mr. Altman from OpenAI’s board and unravel a shift the company recently made to operate as a for-profit company overseen by the original nonprofit.

Mr. Musk argues in his suit that OpenAI — now worth an estimated $730 billion — has abandoned its humanitarian mission in favor of monetary gain. OpenAI says that’s nonsense.

Mr. Musk also tried to recast OpenAI as a commercial enterprise before he left in 2018, according to emails filed as evidence ahead of the trial. And once the A.I. boom arrived, he created his own for-profit lab, xAI. That is now part of the rocket company SpaceX, which is expected to go public as soon as this summer, in an offering worth as much as $1.75 trillion.

The feud between Mr. Musk, 54, and Mr. Altman, 41, is typical of the schisms at A.I. companies over the years. Several times, top researchers have come together with plans to build powerful A.I., before fighting over the best way to do it, parting ways and launching new companies.

“We don’t typically see Silicon Valley companies engaged in scorched-earth tactics in the courts, but Elon is singular,” said Anupam Chander, a professor of law and technology at Georgetown Law. “When the richest man in the world sues you, you’re going to be worried about the suit, even if you feel that you are in the right.”

Satya Nadella, Microsoft’s chief executive, is expected to testify. Shivon Zilis, a former OpenAI board member and the mother of at least four of Mr. Musk’s children, is on the witness list. So is Tasha McCauley, another former OpenAI board member, who tried to fire Mr. Altman.

That Oakland is playing host to this tech industry pantheon is one of the many oddities in this high-stakes trial. While plenty of tech workers live in Oakland, only a handful of tech companies are based in “The Town,” as locals call it. The go-go tech culture of San Francisco and Silicon Valley is notably absent in this city, even though it is only about 12 miles from OpenAI’s headquarters.

“Oakland is an interesting city for this to happen in, because we’re kind of thought of as the other town,” said Lesley Mandros Bell, an artist and teacher who has lived in Oakland for nearly four decades.

The Oakland federal courthouse is part of a soaring, postmodern complex built in 1993 and named for Ronald Dellums, a longtime congressman whose district included Oakland and who served as the city’s mayor from 2007 to 2011. But Mr. Dellums, who died in 2018, might have frowned upon the ruthless capitalism that will be on display in the building named after him. He was a democratic socialist whose politics landed him on President Richard M. Nixon’s “enemies list.”

“We start with a humanistic value system and ask: What inhibits life and growth?” Mr. Dellums said in an interview in 1976. “The answer is war, pollution, elitism, corporate corruption, corporate power that controls over 90 percent of the wealth and dominates people’s lives.”

When Mr. Musk founded OpenAI with Mr. Altman and several young A.I. researchers, he saw the research lab as a necessary counterweight to the A.I. work underway at Google. He believed that Google and Larry Page, one of its founders, did not understand the dangers of A.I.

OpenAI’s founders — backed largely by donations from Mr. Musk — vowed to freely share their technology with the public as open source software. They argued that A.I. would be too powerful and too dangerous to be controlled by a single company.

But by late 2017, many inside OpenAI were arguing that open sourcing may be more dangerous than keeping the technology closed. And they worried that if the lab remained a nonprofit, it might not raise the money needed to reach its lofty goal of building artificial general intelligence, or A.G.I., a machine that can do anything the human brain can do.

That included Mr. Musk. In February 2018, he forwarded an email to the lab’s other founders suggesting that OpenAI attach itself to Tesla, his electric car company, and build its A.I. using the supercomputers that Tesla was developing.

“Tesla is the only path that could even hope to hold a candle to Google,” he wrote. “Even then, the probability of being a counterweight to Google is small. It just isn’t zero.”

After Mr. Altman and others refused to give Mr. Musk control, he quit. Later that month, he announced his departure to OpenAI’s staff on the top floor of the lab’s office in San Francisco. He withdrew his financial support for the lab.

Forced to find other sources of funding, Mr. Altman bolted a for-profit company onto the original nonprofit and eventually raised $13 billion from Microsoft. The lab also curtailed its efforts to open-source its technologies.

OpenAI has since emerged as one of the most important tech companies in the world, worth an estimated $730 billion as a for-profit company overseen by the original nonprofit. The start-up is heading toward one of the biggest initial public offerings in history, which could come as soon as this year.

The company has expanded to more than 4,000 employees working in offices around the world, and is pursuing a data center expansion plan that could cost hundreds of billions of dollars.