Earlier in the day, Google CEO Sundar Pichai said in his own staff email that he is “upset about the impact of this order and any proposals that could impose restrictions on Googlers and their families.” Facebook said through a spokeswoman that it’s “assessing the impact on our workforce and determining how best to protect our people and their families from any adverse effects.” And Microsoft told POLITICO it’s exploring its legal options to help workers affected by the new policy, which temporarily halts the admission of new refugees into the U.S., indefinitely bans refugees from Syria, and suspends the entry of citizens of several Muslim-majority countries.

In Google’s case, at least 187 employees may be affected by the new restrictions, Pichai said in his letter. Microsoft is aware of 76 employees “who are citizens of these countries and have a U.S. visa,” wrote Brad Smith, the company’s president and chief legal officer, in an email to staff on Saturday. Smith added that he and CEO Satya Nadella would discuss the issue further with Microsoft employees next week. Facebook did not have a number immediately available, while Cook said “there are employees at Apple who are directly affected by yesterday’s immigration order,” without specifying how many.

Separately, the chief Washington lobbying arm for the Valley’s major web companies, the Internet Association, registered its dissatisfaction Saturday. “The internet industry is deeply concerned with the implications of President Trump’s executive order limiting immigration and movement into the United States,” said Michael Beckerman, the president of the group, which includes Facebook and Twitter. He added many tech giants retain “legal immigrant employees who are covered by these recent executive orders and will not be able to return back to their jobs and families in the U.S.”

Still, many of tech’s top firms, like Amazon, IBM and Intel, have yet to say anything on the subject. SpaceX, whose founder, Elon Musk, advises Trump on two panels focused on economic issues, declined to comment.

That silence from some has sparked debate in Silicon Valley over its stance toward Trump. Sam Altman, the president of Y Combinator, a prominent tech startup incubator, said the country needs “to hear from the CEOs clearly and unequivocally” over the next week, even if “there is some business risk in doing so.”

“At a minimum, companies should take a public stance,” Altman wrote in a blog post. “But talking is only somewhat effective, and employees should push their companies to figure out what actions they can take.”

Trump’s prohibitions, which generated criticism this weekend from human rights groups and immigration reform advocates, pose a particular challenge for tech giants, which rely on a global workforce and regularly employ foreign engineers, often through the government’s high-skilled immigration programs. For years, tech companies have lobbied for the ability to hire more foreign workers, a push led by Valley titans like Facebook Mark CEO Zuckerberg, who launched the advocacy organization FWD.us to press for immigration reform.

On Friday, Zuckerberg published a note on the social network he founded highlighting his concerns with Trump’s plan. He said the U.S. government should be “focusing on people who actually pose a threat” while advocating policies that “keep our doors open to refugees and those who need help.” The Facebook CEO has previously criticized Trump’s plans to build a wall along the Mexican border, another element of the executive orders signed by the president this week.

Uber CEO Travis Kalanick, who along with Musk is a member of Trump’s so-called Strategic and Policy Forum, told employees in a Saturday email shared with POLITICO that he planned to raise the fact that “this ban will impact many innocent people” with the president on Monday, when the group is set to meet.

Kalanick said Uber has roughly a dozen employees “who live and work in the U.S., are legal residents but not naturalized citizens will not be able to get back into the country if they are traveling outside of the U.S. now or anytime in the next 90 days,” according to the email. But it also affects “thousands of drivers who use Uber and come from the listed countries,” he said, and Uber is working on a “process to identify these drivers and compensate them pro bono during the next three months to help mitigate some of the financial stress and complications with supporting their families and putting food on the table.”

In a tweet, Twitter CEO Jack Dorsey noted late Friday that “11% of Syrian immigrants to the U.S. are business owners, more than triple that of U.S.-born business owners.” In an interview with CNN, tied to Dorsey’s work with the mobile-payments platform Square, Dorsey didn’t mention the president directly. But, he added: “We benefit from integration, we benefit from diversity, we benefit from including more people, because we see different perspectives.”

Other tech leaders, like Stewart Butterfield, the CEO of Slack, and Aaron Levie, the CEO of the cloud storage giant Box, took more precise aim at Trump and his executive order. Citing a tweet about Kellyanne Conway, one of Trump’s top advisers, Butterfield said that “nearly every action seems gratuitously … evil.” And Levie tweeted earlier in the day: “On every level -moral, humanitarian, economic, logical, etc.- this ban is wrong and is completely antithetical to the principles of America.”