New York, New York - A Brooklyn judge will allow a prominent alt-right internet figure to keep his identity secret when he testifies against a pro-Donald Trump Twitter troll accused of trying to trick 2016 Hillary Clinton voters out of casting a ballot.

Judge Nicholas Garaufis ruled that the witness, who prosecutors say "occupied a prominent position within the online, alt-right community," will be identified by just a screen name at Douglass Mackey’s trial this month.

Mackey tweeted official-looking fake campaign ads for Hillary Clinton during the 2016 presidential campaign, urging people to vote by text instead of in person, according to the feds. Opening arguments slated for Monday.

The trial was transferred Sunday from Garaufis to Judge Ann Donnelly, who presided over the sex trafficking trial of disgraced musician R. Kelly in 2021.

Crime Deadly triple stabbing shocks New York City

Mackey’s lawyer tried to get the case tossed on First Amendment and other grounds in October, but Garaufis ruled that the trial would continue.

The cooperating witness plans to testify about being part of direct-message groups on Twitter, coordinating with Mackey on how to trick Clinton voters out of casting a ballot, according to court documents.

He pleaded guilty to conspiracy against rights – the same charge Mackey faces – and is helping the FBI in several other cases, prosecutors said in recent court filings.

Mackey, who went by the handle "Ricky Vaughn" – a reference to Charlie Sheen’s character in the movie Major League – posted memes in an attempt to suppress the vote for Clinton and get Trump elected, the feds say.

"Avoid the Line. Vote from Home," Mackey tweeted on November 1 along with a photo of a Black woman standing in front of an "African Americans for Hillary" sign. The fine print read, "Must be 18 or older to vote. One vote per person. Must be a legal citizen of the United States. Voting by text not available in Guam, Puerto Rico, Alaska or Hawaii. Paid for by Hillary for President 2016."

He and several other trolls went on group chats to workshop how best to design the meme to convince people it was real, the feds allege.

About 4,900 people texted the number in the memes, the feds allege, though it’s not clear if any were tricked into staying home on Election Day.