It’s no secret that the relationship between technology leaders and newly elected President Donald J. Trump has been less than cordial.

Now, it could get downright ugly. “Silicon Valley is stepping up,” Sam Altman, president of the startup incubator Y Combinator, said in the New York Times today.

And some, especially employees, are doing so literally with their feet. According to a number of sources Monday, thousands of tech workers are organizing to march on March 14 (know as Pi Day to the nerdy) to protest Trump and his policies. One organizer, Brad Taylor, a software engineer at the San Francisco startup Optimizely, created Tech Stands Up after getting frustrated about what he and others viewed as tech leaders’ too-timid responses to the president’s travel ban. “I was sick of the silence,” he told Axios.

Prior to Trump’s victory, many leaders in the tech industry made it known they were less than keen on the idea of a Trump presidency. Shortly after the election results sunk in, a dark, ominous pall seemed to hang over the usually blue skies above Silicon Valley. But with some exceptions, such as a protest at Google sanctioned by executives such as Chief Executive Sundar Pichai (pictured, left) and co-founder Sergey Brin (right), they mostly kept their comments, if they made any at all, on the mild side. It was only a matter of time until push came to shove.

The shove was Trump’s immigration ban. It proved to be the catalyst that brought much of the tech industry in from the sidelines, as many execs proclaimed that what their new president wanted was decidedly “un-American.” A federal appeals court in San Francisco will hear arguments on whether to reinstate the travel ban. The hearing will be livestreamed at 3 p.m. Pacific Tuesday.

Update: The court didn’t rule yet, but according to most observers, the panel of three judges seemed skeptical of the Justice Department’s broad defense of the ban. In any case, an appeal to the Supreme Court is expected, and since the high court remains at eight members, a possible 4-4 deadlock would leave the ruling in place.

Trump clearly knows the importance of having tech on his side. He befriended Silicon Valley investor Peter Thiel, held round-table meetings with tech leaders on how they see the future and enjoyed the company of a few “high-powered” tech execs on his business advisory council – now minus Uber Technologies Inc. CEO Travis Kalanick, who quit the council last week apparently under pressure from outraged customers and employees.

But according to Altman, tech is getting prepared to take on Trump in more ways than we might have previously thought: “The companies are working on three fronts: They are vociferously objecting to the Trump policies they think are bad, they are trying to engage with him to influence his behavior, and they are developing new technology to work against policies and political discourse they don’t support.”

Almost 130 tech companies, including big names such as Apple Inc., Microsoft Corp. Google Inc. and lesser-known companies, filed an amicus brief Sunday with the U.S. Ninth Circuit Court of Appeals, stating that Trump’s immigration ban was not only bad for business, but a wrong turn that also happens to violate the U.S. Constitution.

The brief stated that many of the leading companies in the world were started by immigrants or their progeny. It said those people who traveled to America were “endowed with drive, creativity, determination — and just plain guts. The energy they bring to America is a key reason why the American economy has been the greatest engine of prosperity and innovation in history.”

Although tech companies may be among the most public in their opposition to some of Trump’s proposals, particularly on the immigration front, they’re hardly alone. During the Super Bowl, several companies ran (or tried to run) ads that appeared to pointedly endorse immigrants. Here’s one of them, from 84Lumber:

The tech industry often has led big changes in the way business gets done. Whether it can do the same in politics may depend less on technology than old-fashioned feet on the street.

Photo courtesy of William Ruckledge/Twitter