The decision by President Donald Trump to impose a broad immigration ban on seven countries may have an impact he didn't foresee.The ban, a 90-day moratorium on admissions and re-entry in the United States unveiled on Friday, isn't about H-1B visa-holders specifically. And it doesn't grow out of the his voiced concerns about the use of that visa to displace U.S. workers. Instead it affects tourists, business and student visas. Those with permanent residency, or green cards, are also affected.Trump's ban, issued through an executive order, affects all visa types in seven countries: Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen. The action is ostensibly intended as an anti-terrorism measure. It targets some, but not all, Muslim-majority countries; Saudi Arabia, for instance, is not on the list.Aside from inflaming civil liberties groups, sparking court fights and spontaneous demonstrations last night at various U.S. airports, the move is also giving the tech industry a renewed voice and a rallying point on immigration. This comes at the same time the Trump administration is expected to begin pushing for H-1B reforms.Among those speaking out was Twitter CEO Jack Dorsey, whose Twitter feed included a steady stream of retweets critical of Trump's action."The Executive Order's humanitarian and economic impact is real and upsetting. We benefit from what refugees and immigrants bring to the U.S.," wrote Dorsey, and "This EO goes against our principles."The tech leaders looked beyond the seven-country ban to make a broad push for immigration reform. Facebook CEO Mark Zuckerberg urged Trump to help the "750,000 Dreamers benefit from the Deferred Action for Childhood Arrivals (DACA) program that allows them to live and work legally in the US. I hope the President and his team keep these protections in place."A federal court ruled late Saturday that the U.S. could not deport citizens of the banned countries who had already arrived in the U.S. It was prompted by a lawsuit filed by the American Civil Liberties Union.Trump's move was put into place so fast it literally affected people in transit."This was done with almost no notice," said Carl Shusterman, a Los Angeles-based immigration attorney. He said his office received a leaked draft of the executive order last Tuesday and began advising people about what was in the pipeline."I think this is causing a lot of chaos for really no reason at all," said Shusterman.Trump's order prompted tech firms to scramble to locate and notify affected employees, and to issue statements over the weekend."As an immigrant and as a CEO, I've both experienced and seen the positive impact that immigration has on our company, for the country, and for the world," wrote Microsoft CEO Satya Nadella in a posting on LinkedIn on Saturday. "We will continue to advocate on this important topic."Microsoft said it has identified 76 employees who are citizens of the seven countries who have a U.S. visa and are affected. But it also said there may be other affected employees who have green cards.The seven countries cited by the Trump administration have had no role in the ongoing H-1B visa debate. In 2014, nearly 70% of all H-1B visas were issued to people born in India, according to U.S. data.Ron Hira, associate professor of public policy at Howard University, ran an analysis of the visas issued in the 2013 fiscal year alone and found a total of 1,220 H-1B visas, new visas or renewals, from workers in all seven countries.In that year, Iran had the largest number of visa holders, with 810. It was followed by Syria, with 280; Libya, with 53; and Iraq, at 46. The Sudan accounted for 18 visas; Yemen, 11; and Somalia, 2.In 2013, Microsoft was the top employer of H-1B-visa workers from the seven countries, with 31. It was followed by Qualcomm at 21, and Google at 15, according to Hira."The Iran numbers suggest to me that it is foreign students who graduated from U.S. universities" as well as having family ties in the U.S., he said.Iran's Foreign Ministry, in a statement carried by Iranian media, called the U.S. move "insulting" and an "open affront" and said it is considering a reciprocal response.The Trump order also has broad impacts."If a company wants to hire a worker from one of those countries, they won't be able to get a visa for at least 90 days," said Stephen Yale-Loehr, a professor of immigration law practice at Cornell University. "Foreign national employees on work visas who are temporarily overseas may not be able to return."The Computing Research Association, in a statement, warned that the Trump order "may also discourage foreign-born researchers from bringing their talents to the U.S. in the future, which would have significantly detrimental impacts on our national competitiveness."