The homepage of the American Civil Liberties Union's website on November 9. aclu.org The American Civil Liberties Union has received a record 14,000 online donations totaling $940,000 since Donald Trump's upset victory Tuesday evening.

"In terms of online donations in a single-day, it far exceeds anything we've seen before," the ACLU's chief development officer Mark Weir told Business Insider in a statement.

Donations skyrocketed on Wednesday after the organization published a harsh message for the president-elect, promising its "full firepower" should Trump seek to undermine the Constitution or violate Americans' rights with the proposals he campaigned on.

A message emblazoned on the homepage of the ACLU's website read "See you in court" next to Trump's photo, with a "Donate" button underneath.

The ACLU warned Trump that it will be "eternally vigilant every day of your presidency" and will "never waver" from protecting Americans' Constitutional rights.

The statement was in stark contrast to the conciliatory tone many of Trump's harshest critics took on Wednesday after his upset victory.

In the statement, the ACLU listed several of Trump's campaign promises, including his promise to assemble a deportation force to remove 11 million undocumented immigrants, bar Muslims from entering the country, "open up" libel laws to allow him to more easily sue news organizations, and bring back waterboarding and other forms of torture.

Such initiatives, were they implemented, would violate the First, Fourth, Fifth, Eighth, and 14th Amendments, and would be "un-American and wrong-headed," the ACLU wrote.

"It you do not reverse course and instead endeavor to make these campaign promises a reality, you will have to contend with the full firepower of the ACLU at every step," the organization's executive director Anthony Romero wrote.

"Our staff of litigators and activists in every state, thousands of volunteers and millions of card-carrying members and supporters are ready to fight against any encroachment on our cherished freedoms and rights."

Users took to Twitter on Wednesday to announce donations to the ACLU, as well as other charities and nonprofits.