I don't have to run the experiment. I can already tell you that anything said in Hacker News comment threads doesn't threaten the government or much of anyone, really.
You misunderstand: he has the freedom to speak, so long as he has no voice.
Say whatever you want whenever you want; they're watching, but don't care enough to interfere if you're a nobody. Nobody will bother you until you have a following, and nobody will bother you in meatspace until you have a massive and physically active following.
Let's try an experiment: you post some of the things that you think aren't being said, and we'll all see what happens.