In an open letter posted to Microsoft’s internal message board... more than 100 employees protested the software maker’s work with Immigration and Customs Enforcement and asked the company to stop working with the agency, which has been separating migrant parents and their children at the border with Mexico. “We believe that Microsoft must take an ethical stand, and put children and families above profits,” said the letter... The letter pointed to a $19.4 million contract that Microsoft has with ICE for processing data and artificial intelligence capabilities... The letter is part of a wave of tech workers mobilizing this week against the Trump administration’s new “zero tolerance” policy that refers for criminal prosecution all immigrants apprehended crossing the border without authorization... At Silicon Valley companies including Google, Apple and Facebook, employees have in recent days circulated internal emails asking for donations to nonprofit groups that support immigrants... The activity has had an effect. Late on Tuesday, after Microsoft’s employee letter went up, the company released a memo from Mr. Nadellain which he called the immigration policy “cruel and abusive” and said Microsoft was not working with the federal government on any projects to separate families. Microsoft’s president, Brad Smith, also published a blog post titled, “The Country Needs to Get Immigration Right.”...On Facebook, two former employees of the social network started a fund-raiser on Saturday to collect $1,500 for migrants who needed legal assistance because of the new policy. By Tuesday afternoon, the effort had garnered more than $5 million from donors who included numerous tech workers.