What about: yelling "fire" in a crowded room, deliberately lying on the internet in a way that leads to deaths (ex. 4chan's "how to grow crystals" post), targeting kids or at risk groups with ads or content for things like gambling, alcohol, etc., calling for someone's death, posting instructions for making a bomb?
Yep, that’s pretty dangerous, and people could get hurt. That shouldn’t be protected by the First Amendment.
Oh yeah, and protesting the draft. That’s pretty dangerous too. Government military recruitment is a necessity when we’re at war, and advocating against it is tantamount to sedition and espionage. It’s basically the same situation as shouting “fire” in a crowded room, and should not be protected by the First Amendment.
Now, I don’t actually believe this—I’m merely sharing how the US Supreme Court used exactly the same analogy you did, in 1919. Schenck v. United States is the most important use of the “‘fire’ in a crowded theater” analogy in history, because it shows how, in practice, such common‐sense ideas actually get used by the powerful.
At that point, why bother to allow gambling or alcohol a place in society. If people truly have no self determination, why not let a state or federal agency dictate all of their rights and wrongs. Eat only what's good for you because if it isn't healthy and slimming, you can't say anything about it because obese people are an "at risk" population. No more addictive medications of any kind. Doctors aren't agents of the state and couldn't possibly be as educated as a government representative, like your congressman. And intimating that your government officials lied to the public at large would be strictly verboten, I'm sure.
Okay let's say you're right: no one can really define "at risk" so that's fine. What about kids? Can I seek out kids online and directly engage them in their DMs and tell them how awesome gambling, drugs, and guns are? I have links to all these sites (and phone numbers for totally reputable guys) they should remember for when they turn 18 that I will send them.
Drugs ate pushed on television stations a hundred times a day. There are so many commercials for drugs, it's disheartening. There are adds to be more beautiful, thinner, more muscular with drugs and products that promise all of these things. Syrupy sugar drink commercials and fast food restaurants are plastered on TV and print all day, everyday. All for the kids to see.
Don't forget the evils of "harmful lyrics" that Tipper Gore saved us from. That was teaching children forbidden concepts like inner city music and dangerous metal music.