The arrest was an early triumph for the growing community of self-proclaimed sedition hunters—a motley assortment of internet sleuths who have spent hundreds of hours analyzing the reams of footage that emerged from the insurrection. Over the past few months, the sleuths have coalesced into an expansive network that shares and cross-references videos and social media posts, dissecting the material on Twitter or in private group chats on platforms like Discord. “Every person brings a piece of the puzzle together,” Sigurdson says. “People are only able to really hone in on somebody based on the work that everyone else is doing.”... Five months on from Jan. 6, the authorities have brought charges against more than 400 rioters, often using the traditional tools of law enforcement, such as search warrants and confidential informants. But they’ve also relied on the crowdsourcing efforts of sedition hunters. In the days after the riot, the FBI saw a 750% increase in daily calls and electronic tips to its main hotline. The bureau still receives twice the normal volume of alerts. Such tips have proved helpful in “dozens of cases,” says Samantha Shero, an FBI spokeswoman. “The public has provided tremendous assistance to this investigation, and we are asking for continued help to identify other individuals.” Many of the sleuths have treated the project as a full-time job, creating infrastructure to help fellow investigators sort through the footage. A sedition hunter in California built a facial recognition database that the community has used to identify rioters. (The site’s tagline: “They should have worn some f#$!ng masks.”) Such tactics have sparked concern among civil liberties advocates, who argue that the proliferation of facial recognition technology has eroded privacy. The database’s creator, who works in the health-care industry, defended the tool, saying it simply automated the time-consuming process of cross-referencing Jan. 6 images. He used the technology to identify Taylor Johnatakis, a podcaster from Washington state who was later charged for his role in the siege. (Johnatakis pleaded not guilty.) The creator says he felt a civic obligation to alert the FBI but took no joy in Johnatakis’s arrest. “He’s an honest-to-God good guy, completely brainwashed by Trump,” he says. “I hope the justice system is forgiving.”