In late October 2017, a Department of Homeland Security agent emailed intelligence centers asking if they had any information about a supposed anti-fascist plot to overthrow the government seen on YouTube.

The supposed plot was a Nov. 4 protest that, for weeks, had been the subject of a left-right meme war. Some research by the DHS agent would have revealed the actual protest to be a dud, planned by a small group. But the emails, retrieved by Freedom of Information Act request by the transparency nonprofit Property of the People, suggest some DHS staff took the memed-up threat seriously.

The emails might be funny if they didn’t suggest a direct trail of misinformation leading from right-wing internet circles to government officials.

"There are currently a large number of Youtube videos related to an unconfirmed nationwide plan by ANTIFA to cause disruptions on November 4, 2017,” read one Oct. 25 email from a DHS senior special agent to DHS intelligence centers in Maryland and Virginia. “Some videos claim there is a plan to overthrow the government and/or harm law enforcement officers."

It’s not clear which YouTube videos the agent viewed and DHS did not respond to The Daily Beast’s request for comment. But in the previous weeks, a wealth of right-wing videos had appeared on YouTube, many claiming the left was plotting a civil war.

“CIVIL WAR IS COMING - Patriots beware November 4!” one video, uploaded October 4 by the channel Catholic Online warned. The clip, which claimed anti-fascists were planning major demonstrations, currently has more than 50,000 views. Other outlets, including Infowars, the far-right John Birch Society, and people selling survivalist guides, also characterized Nov. 4 as a looming threat.

“We have a flood of antifa saying that they’re preparing with weapons, knives and guns to kill conservatives, patriots and white people en masse,” Infowars host Alex Jones said on September 29.

The only problem: the protest had virtually no support. The demonstration was the work of Refuse Fascism, an offshoot of the Bob Avakian-led Revolutionary Communist Party.

“U.S. agencies have long relied on industry and far-right sources for dubious ‘intelligence’ used to target social justice activists as security threats,” Ryan Shapiro, executive director of Property of the People, told The Daily Beast “This has prominently included agencies relying on Big Oil and the fur industry for information used to target peaceful animal rights and environmental protesters as terrorists. With the new documents, we see U.S. intelligence agencies treating the hysterical ravings of random right-wing Redditors and YouTube videos as a legitimate basis for targeting anti-fascists as threats to the state.”

Despite its name, Refuse Fascism is largely disconnected from other grassroots progressive and anti-fascist groups that show up at demonstrations, and is sometimes regarded with frustration by members of these other groups. Its planned Nov. 4 demonstration attracted little interest from other activists groups. Anecdotally, when a Refuse Fascism member attempted to promote the demonstration at a panel on progressive activism this reporter attended in Manhattan last September, moderators interrupted, with one panel member encouraging the audience not to donate to Refuse Fascism.

Already something of a joke in leftist circles, the protest became a Twitter meme in late October 2017, with leftist users posting increasingly impossible claims about the supposed civil war. “Can’t wait for November 4th when millions of antifa supersoldiers will behead all white parents and small business owners in the town square,” popular comedy account KrangTNelson tweeted.

More right-wing media picked up on the meme. “ANTIFA Leader: ‘November 4th […] millions of antifa supersoldiers will behead all white parents’” read one Gateway Pundit headline.

By then, multiple news outlets had reported the antifa civil war to be a hoax. “Antifa Supersoldiers” and the Nov. 4 rally received its own writeup on Know Your Meme, a meme documentation site.

Still, sometime during the meme-storm, the DHS agent observed “a large number of Youtube videos” about “a plan to overthrow the government and/or harm law enforcement officers.” Emails from other DHS officials in response to the agent’s request for more information are redacted.

But other DHS documents retrieved via FOIA request provide a fuller picture of the department’s intelligence-gathering ahead of the Nov. 4 demonstration. The day before the demonstration, DHS agents circulated a list of groups supposedly protesting. The list appears to be culled from Facebook: it includes an event sponsored by the page The Resisters, which was later purged from Facebook for its complicated relationship with a suspected Russian troll account. The Resisters-hosted event would have 40 participants (likely the number of Facebook event RSVPs), according to the DHS document.

Other events listed in the document include a rally called “Promote Love, Not Hate,” which promised five participants, and Anonymous’s “5th Annual Million Mask March,” which, despite its name, only planned for 121 participants. The largest event on the list was a planned 1,000-person march from the group “White People Marching for Black Lives.” No trace of the group remains of the group online, and old links to what appears to be the event page show the march had cancelled on the 1,000-plus people who RSPVed.

But DHS’ understanding of anti-fascism—a broad, decentralized movement that conservative blogs often describe in sensational terms—might be less than perfect. An April 19, 2017 DHS email included in the FOIA documents shows a DHS senior policy adviser sending a link to a post on the now-defunct conservative blog Heat Street titled “Why Are Antifa And The Alt Right Doing Battle? They Agree on Almost Everything.”

The U.S. Secret Service was also monitoring the November 4 event in the immediate days before, FOIA documents show. An Oct. 27 Secret Service document reviewed by The Daily Beast correctly identified the demonstration as originating with Refuse Fascism. But it also cites Reddit comments from far-right users.

“In my opinion… we should all be arming ourselves and taking to the rooftops and streets,” reads a Reddit comment the Secret Service identified as originating from an alt-right user. “Let them fire the first shot and then let those pathetic commie bastards know we mean business.”