He didn't threaten to do it, he did it
Conspiracy, by definition, is talking about commiting a crime, and then doing an action to actually commit the crime.
So let's say I get some friends together and we talk about pulling a heist on the local art museum. That in and of itself is not a crime, we are just talking. But if we start going out and casing the joint, buying crow bars and shit to actually do it, it becomes a conspiracy to commit burglary, which is a crime. Even though we didn't actually break into the place yet, it becomes a crime when we make actions toward the crime.
Dude made statements about overthrowing the government. Not a crime. But then he went to the government and started jumping fences, and breaking into buildings. Crime.
Also, by your logic yelling fire wouldn't be illegal, it's literally speech. Also threatening is a crime. If I say, I'm gonna hit you with this hammer, and I have a hammer in my hand, that is assault, which is totally a crime. Didn't actually hit you, just threatened to but with the clear ability to go through with that threat.
Christmas creping into October. Like it already dominates all of December and November, leave Halloween alone.
People at work were talking about going to a store that already has Christmas stuff set up. It's getting ridiculous...