• Amazon, Meta, and OpenAI CEO Sam Altman have all announced $1 million donations to Trump's inauguration fund.
• Tech execs have been working to smooth relations with Trump, who has been an open critic of particular companies in the industry.
• Altman is in a heated legal battle with Elon Musk, who became one of Trump's biggest backers and could have outsized control in his administration.

Meta CEO Mark Zuckerberg and Amazon founder Jeff Bezos have a particularly sketchy past with President-elect Donald Trump. OpenAI CEO Sam Altman is in a heated legal battle with Elon Musk, who became one of Trump's biggest backers and is poised to have an outsized role in his second administration.

That all helps explain announcements this week regarding donations to Trump's inauguration fund.

"President Trump will lead our country into the age of AI, and I am eager to support his efforts to ensure America stays ahead," Altman said in a statement Friday. Altman said he's planning to make a personal donation of $1 million to the fund, the company confirmed.

Meta donated $1 million to the inauguration, the company confirmed to CNBC, weeks after Zuckerberg dined with Trump privately at his Mar-a-Lago resort. Amazon is also planning to donate $1 million, according to a report from The Wall Street Journal.

Trump has been a vocal critic of tech companies, and he signaled earlier this month that he won't shy away from antitrust enforcement. The incoming president nominated Gail Slater, who advised Trump on tech policy during his first term, to head the Department of Justice's antitrust arm.

"Big Tech has run wild for years, stifling competition in our most innovative sector and, as we all know, using its market power to crack down on the rights of so many Americans, as well as those of Little Tech!" Trump wrote in a Dec. 4 post on Truth Social announcing Slater's nomination. "I was proud to fight these abuses in my First Term, and our Department of Justice's antitrust team will continue that work under Gail's leadership."

Some of Trump's most hostile words in the past have been directed at Amazon and Meta.

In his first term, Trump repeatedly attacked Bezos and his companies, Amazon and The Washington Post, accusing them of dodging taxes or publishing "fake news," among other things. Trump also repeatedly pointed the finger at Amazon for its use of the U.S. Postal Service to deliver packages to customers, claiming the company contributed to the post office's budget problems.

The animosity went both ways. In 2019, Amazon blamed Trump's "behind-the-scenes attacks" against the company for its loss of a multibillion-dollar Department of Defense contract, then called JEDI. And prior to the 2016 election, Bezos criticized Trump's behavior, saying it "erodes our democracy." After the then-Republican candidate accused Bezos of using the Post as a "tax shelter," Bezos, who also owns the Blue Origin space company, in a tweet offered to send Trump into space on one of his rockets.

Blue Origin competes for government contracts with Musk's SpaceX.

At The New York Times' DealBook Summit on Dec. 4, Bezos said he expects a more friendly regulatory environment in the upcoming administration.

"I'm actually very optimistic this time around," Bezos said on stage. "He seems to have a lot of energy around reducing regulation. If I can help do that, I'm going to help him."

Trump has called Bezos "Jeff Bozo." His preferred nickname for the Meta CEO is "Zuckerschmuck."

Following Trump's loss in the 2020 election, he sued Facebook, Twitter and Google, as well as their respective CEOs in class-action lawsuits. All three companies booted Trump's accounts from platforms after the Jan. 6, 2021, riots at the Capitol.

Trump has long accused Facebook of silencing conservative voices. In March, he called the platform "the enemy of the people along with a lot of the media," in an interview on CNBC's "Squawk Box."

Now that Trump is heading back to the White House and has been cozying up with Musk, the rest of the tech sector seems keen on currying favor. Apple CEO Tim Cook, Microsoft CEO Satya Nadella, Google CEO Sundar Pichai and others all publicly congratulated Trump following his victory in November.

Microsoft declined to comment on whether it's contributing to the inauguration. Representatives from Apple and Google didn't immediately respond to CNBC's requests for comment.

For OpenAI and Altman, the concerns are a bit different. Altman and Musk were co-founders of OpenAI, which initially was a nonprofit. The two have since publicly split, with Altman remaining as CEO of OpenAI and Musk starting a rival artificial intelligence company called xAI.

In March, Musk sued OpenAI — and co-founders Altman and Greg Brockman — alleging breach of contract and fiduciary duty. He claimed the project had been transformed into a for-profit entity that's largely controlled by principal shareholder Microsoft, and is suing to thwart the change in structure.

OpenAI clapped back on Friday, claiming in a blog post titled "Elon Musk wanted an OpenAI for-profit," that in 2017 Musk "not only wanted, but actually created, a for-profit" to serve as the company's proposed new structure.

Altman's coming concern is that Musk spent more than $250 million to help boost Trump's campaign, and is now poised to help lead the "Department of Government Efficiency." In that role, Musk could influence how AI is regulated in ways that favor his businesses.

On Dec. 5, Trump announced that venture investor and podcaster David Sacks, a friend of Musk's, will join the Trump administration as the "White House A.I. & Crypto Czar."

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