A frenzied scene materializes four days a week at the Fairfax County Courthouse in Virginia as fans seek seats at the defamation trial between Johnny Depp and his ex-wife Amber Heard.

The line to enter the courthouse begins before sunrise. Throughout the day, people appear carrying signs, wearing fan merch and costumes, even walking a pair of alpacas. Nearly all of them are there for Mr. Depp.

“We just want to support our captain,” said Jack Baker, 20, who arrived on Monday dressed like an extra in “Pirates of the Caribbean” to film footage for his YouTube channel. “If he goes down with the ship, we’re going down with him.”

Maryam Alam, 29, and Alina Alam, 29, had hoped to get into the courthouse, but when they showed up at 7 a.m. they were already too late. Both grew up watching Mr. Depp onscreen — playing such characters as Edward Scissorhands, Captain Jack Sparrow, Willy Wonka — and were eager for the chance to see him in person.

“It’s fulfilling a childhood fantasy,” Maryam said. “It’s the reason why everyone else is here.”

High-profile celebrity cases have drawn a wide audience ever since Court TV began broadcasting from courtrooms in the 1990s. But the trial of Mr. Depp and Ms. Heard has become a case study in what happens when complex claims are filtered through the lenses of stan culture and social media.

In addition to the live coverage on TV, YouTube, and various news and entertainment websites, countless short clips edited for maximum virality have circulated on Instagram and TikTok — “fancams,” in social media parlance, featuring forensic analyses of Mr. Depp’s and Ms. Heard’s trial attire, and courtroom exchanges that have been described as “SAVAGE.”

Mr. Depp, 58, is suing Ms. Heard, 36, over an essay she published in The Washington Post in 2018 about sexual violence, in which she described herself as a “public figure representing domestic abuse.” Though Mr. Depp was not named in the article, he has argued that it clearly alluded to him, damaging his reputation and career. (Ms. Heard filed for divorce in 2016 and, soon after, for a restraining order against Mr. Depp, which she was granted.) In his testimony, Mr. Depp denied ever striking Ms. Heard and argued that she was the aggressor in their relationship. The jury is simultaneously considering a defamation countersuit by Ms. Heard against Mr. Depp.

Many of the accusations were aired in 2020, during a libel case Mr. Depp brought against The Sun, a British newspaper that ran a headline referring to him as a “wife beater.” The judge ruled that the defendants had shown that what they published was “substantially true,” and Mr. Depp lost the case.

While the jury in Virginia has been instructed to carefully weigh the evidence and reach a verdict only after testimony is complete (Ms. Heard has yet to take the stand), and fan-observers have been advised not to react audibly or visibly to either party in the courtroom, the rest of the world is under no such obligation.

In a TikTok video captioned “AMBER HEARD CAUGHT LYING AGAIN,” Ethan Trace (2.8 million followers) gleefully recounts how Ms. Heard’s lawyer said in court that the actress used a makeup palette to cover up bruises Mr. Depp gave her during their marriage. The lawyer held up a palette to reinforce her point, and while she did not name the brand, it was identifiable in photos and video from the trial, and internet sleuths quickly named the company, Milani Cosmetics.

Milani, the brand, later released a TikTok video that stated the product Ms. Heard’s lawyer showed did not become available until after the couple had separated. (“Milani Cosmetics is not taking a formal stance on the trial, evidence or future outcome of the case,” a spokeswoman wrote in a statement.)

“Boom!” Mr. Trace says in the video. “Milani Cosmetics: We love you! Thank you for sharing this!” The video has more than 16 million views.

In an email, Mr. Trace explained that he felt Mr. Depp had been treated unfairly by the media. “How could no one be talking about evidence that could possibly prove a man’s innocence after being labeled an ‘abuser’ in the eyes of the public?” he wrote.

On April 13, shortly after testimony began, Gawker noted that the TikTok hashtag #justiceforjohnnydepp had received 1.1 billion views. In two weeks, that number has more than quadrupled. As of this writing, #justiceforamberheard has 22 million views.

Ms. Heard’s supporters hope that her testimony will shift the dialogue surrounding the trial. “Instead of looking at all these TikToks and everything, I think that people should actually follow the case,” said Carmen Diamandis, 22.

“Stans will literally go to any extent to defend anyone,” he said of Mr. Depp’s supporters, adding: “Amber Heard, she has not got that fan base.”

Marianne Nafsu, 32, a true crime content creator from Detroit who has posted about the case, said: “I can’t wait to hear her side when she stands trial.” She added that “it’s only fair to listen to both sides and see: Where’s all this coming from?”

When asked for a comment on the fan response, Ms. Heard’s lawyers provided her friend Eve Barlow, a music journalist who has been tweeting in support of Ms. Heard.

“The social media landscape is shockingly brutal for Amber,” Ms. Barlow wrote in an email, adding that many of the comments on TikTok and Twitter reflect “misogynist hate.” Mr. Depp’s representatives did not respond to a request for comment.

Rachel Louise Snyder, the author of “No Visible Bruises: What We Don’t Know About Domestic Violence Can Kill Us,” acknowledged in an interview that Mr. Depp has certain advantages over Ms. Heard in the court of public opinion.

“People will dispense with the same critical eye that they would give anybody else when it comes to someone who is really a beloved figure,” she said. Ms. Snyder added that the case offers a potential counternarrative to common misconceptions of abuse: who can perpetuate it and who can be a victim.

“We don’t think about victims as wealthy. We don’t think about victims as men. We don’t think about perpetrators as women,” she said. “I’m not saying that she’s a perpetrator and he’s a victim. I’m just saying that we have an opportunity to look at our own myths and stereotypes around ‘Who’s the victim and who’s the perpetrator?’” (Abuse affects one in four women, according to the National Domestic Violence Hotline, and one in seven men.)

On TikTok, many of Mr. Depp’s supporters have posted about a recording in which Ms. Heard says: “Tell the world, Johnny, tell them, ‘I, Johnny Depp, a man, am a victim too of domestic violence,’” and continues, “See how many people believe or side with you.”

Scout Robert, 24, was taken aback by Ms. Heard’s words. “When she said that, she made the statement to the world that as a man, you cannot be abused,” she said in an interview. Ms. Robert, who has more than 40,000 followers on TikTok, has posted numerous videos on the platform, in which she has called Ms. Heard a liar, abuser and hypocrite. Some have been viewed hundreds of thousands of times.

Ms. Robert said she felt that the #MeToo slogan “believe women” had become overused. Rather, she said, people ought to “listen to women,” while acknowledging “that men can be victims of domestic abuse as well.”

Ms. Snyder, likewise, thinks the Depp trial could spur more nuanced conversations about abuse, and how it doesn’t always fall within neatly prescribed boundaries.

“Maybe he’s a victim, maybe he’s an abuser, maybe he’s a little bit of both,” she said. “Same for her.”

Michael Lee Pope contributed reporting from Fairfax, Va.