Virginia man Fi Duong already faces charges for his minor role in the Jan. 6 attack on the U.S. Capitol. But he may be in more trouble for his actions since Jan. 6, after the FBI infiltrated his “Bible study” group in which participants talked about surveilling the Capitol, making Molotov cocktails, and creating “a semi-autonomous region” in Virginia.

On Jan. 6, Duong told an undercover Metropolitan Police officer that he was an “operator” who was dressed in black to look like antifa. Images then show him in a restricted area outside the Capitol and inside the building itself. Following that, through Duong, an undercover FBI agent gained access to a “loosely affiliated, unnamed group of like-minded individuals,” attending meetings and participating in encrypted chats in which the group planned—or, perhaps more realistically, fantasized about—terrorism following on the Capitol attack.

”How do we feel about an Intel run around the Capitol tonight?” the FBI said one group member wrote in the chat. “Fewer of them out. Posture may be lowered. Good opportunity to expose weaknesses.”

On another occasion, the FBI agent saw cases of glass bottles and heard Duong and another group member talk about using them to make Molotov cocktails. Duong and the agent discussed plans for testing the as-yet-unmade explosives, but did not follow through.

The thing is, the FBI has a proven track record of infiltrating groups of people who are never going to carry out the acts they’re fantasizing about, encouraging them to engage in even more violent fantasies, and then arresting them as terrorists. That’s a thing, and it’s relevant that Duong has not yet been charged for any of this. But Duong already participated, in however minor a way, in a historic act of domestic terrorism, and the FBI does have to take seriously the threat that new groups will emerge from that day, emboldened by the Trump mob’s ability to storm the Capitol and overwhelm police in doing so.

Far-right terrorism is a major threat in the U.S. today. There are secretive militias plotting violence. One fascist group is committing vandalism and marching on major cities. Extremist dreams of reconfiguring the states to give them new territory are gaining steam. And the attack on the Capitol was driven by organized conspiracies from groups like the Proud Boys and Oath Keepers. In that environment, a group with members stockpiling weapons, discussing how to make and test explosives, and doing “an Intel run around the Capitol” has to be taken seriously.