I think these people don't understand free speech. Free speech means I can freely claim that, for example, 9.8 m/s^2 is the acceleration due to gravity here on

I think these people don't understand free speech. Free speech means I can freely claim that, for example, 9.8 m/s^2 is the acceleration due to gravity here on this rock we call Earth. But it also means that someone else can claim that my estimate for the acceleration of gravity here on Earth is BS. The "correct"-ness or the "incorrect"-ness of your speech is irrelevant. People can say whatever they want about you. You can't say that someone calling BS on my estimate for the acceleration due to gravity is harmful to free speech. No. It IS free speech. We can all say what we want. And others can say what they want. Including calling what I say BS, or lies, or misinformation. When you want to prevent others from being able to claim you are promoting BS, you are trying to restrict Free Speech.