The ACLU has fought Trump’s executive order banning immigrants and refugees from seven Muslim-majority countries from entering the US.
Twitter CEO Jack Dorsey and chairman Omid Kordestani each pledged to match a $530,000 (£422,675) donation from 925 staff at the Silicon Valley firm.
Vijaya Gadde, Twitter’s general counsel, wrote in a company-wide email obtained by TechCrunch: “Our work is far from done. In the coming months we’ll see a flurry of legal challenges, legislative pushes and public pronouncements.
“But as long as civil liberties are threatened, I’m proud to know that as individuals we will stand up to defend freedom and look after people.”
Twitter is far from alone among Silicon Valley firms in criticising the executive order. In recent days, US taxi firm Lyft, Google and a number of industry figures have donated millions of dollars to the ACLU.
Bloomberg reported today (2 February) that US firms including Facebook, Microsoft, Google, Apple and Amazon are circulating a letter that pours scorn on the immigration order and offers help to fix it.