Staff at social media company Twitter have donated more than $1m (£790,000) to the American Civil Liberties Union.
The ACLU has pledged to fight President Donald Trump's temporary ban on refugees and immigrants from seven Muslim-majority countries.
The civil rights group has reportedly raised more than $24m in online donations in the past few days.
Taxi hailing company Lyft previously said that it would donate $1m to the ACLU over the next four years.
Nearly 1,000 Twitter employees donated more than $500,000, which was matched by chief executive Jack Dorsey and executive chairman Omid Kordestani, according to TechCrunch.
In an email sent to Twitter staff and obtained by the tech news website, lawyer Vijaya Gadde said: "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."
It is also reported by Bloomberg that some of the largest US technology companies are preparing an open letter to President Trump, expressing concern about his order on immigration and offering help to "fix it".
Meanwhile, messaging platform Viber has offered free international calls to the affected countries - Iraq, Syria, Iran, Libya, Somalia, Sudan and Yemen.