Defined as dangerous because:

https://www.slatestarcodexabridged.com/I-Can-Tolerate-Anythi...

What's the harm in a post-truth society? It's a memetic virus that is spreading. Misinformation was weaponized before flat earth took off. However flat earth is the embodiment of 2 + 2 = 5.

Because nowadays, anyone gets called a conspiracy theorist if they challenge establishment narratives. You get conflated with them, just like you got conflated with extremists/terrorists if you were antiwar (think invasion of Iraq).

Covid policies are extremely authoritarian but you can only challenge them to require MORE security theater, not less. Else, you're labeled and, as OP said, you're dangerous. Your IDEAS are Dangerous. Just like when reading communist books made you dangerous. Several dictatorships knew it was necessary to disappear such dangerous people with their dangerous thoughts.

Anti intellectualism is at its all time high when it comes to "not questioning 'the science'" (The gov/Big tech/state health institutions/state media)