[Updated: Following the publication of this piece, Tesla and SpaceX, both of which have Elon Musk as CEO, joined the amicus brief as signees. Along with them, nearly 30 more companies signed onto the brief, including Slack. Still not involved are Palantir, Oracle and IBM.]

Where are Elon Musk, Peter Thiel, Ginni Rometty, and Safra Catz? That's the big question following the Sunday filing of an amicus brief signed by nearly 100 technology companies in opposition to President Trump's executive freeze on refugees, immigrants, and travelers from Muslim countries.

The court document is strongly critical of Trump's anti-immigration executive order, calling it both bad for business and unlawful. In total, there are 97 companies attached as signees to the brief, which was filed in support of a lawsuit by the state of Washington against President Trump. The companies include everyone from Apple and Google to Twitter and Zynga.

"The Order makes it more difficult and expensive for U.S. companies to recruit, hire, and retain some of the world's best employees," the filing reads. "It disrupts ongoing business operations. And it threatens companies' ability to attract talent, business, and investment to the United States."

Though almost every major tech company is represented, there are five companies that are noticeably missing -- Tesla, SpaceX, Palantir, IBM, and Oracle. And among the leadership of each of those companies, each one has a direct tie to the Trump Administration.

Leading Tesla and SpaceX is Musk, who is the CEO of both companies. Musk is also a member of Trump's business council. Meanwhile, Thiel is the chairman of Palantir. During the campaign season, Thiel was Trump's most prominent Silicon Valley supporter, and he served as part of the president's transition team. Oracle co-CEO Safra Catz was also part of the transition team. And Rometty, who is the chairwoman, president, and CEO of IBM, is also currently a member of the Trump business council.

The only other notable tech company missing from the brief is Amazon, but that's because the Seattle tech giant is listed as a witness for the original lawsuit. That makes Amazon's opposition of the order loud and clear.

Also included in the filing is Uber, the ride-hailing tech giant. Until last week, Uber CEO Travis Kalanick had also been involved in the Trump business council, but he quit his advisory role after Uber was hit with a boycott by users who disagreed with the Muslim ban. Kalanick's leadership team includes two former refugees.

The tech industry is far from a monolith when it comes to politics and policy, but it's telling that the only companies that do not oppose the Muslim ban are the ones whose leaders believe they have the president's ear.

Musk has argued that his position on the council gives him a direct link to Trump, allowing him to raise the controversial topics such as the Muslim ban and climate change, which might have otherwise been ignored by the administration.

"Activists should be pushing for more moderates to advise President, not fewer," Musk said on Twitter Sunday morning. "How could having only extremists advise him possibly be good?"