There are some sights on Tumblr you have to have a "age verification" but I don't ever remember seeing a "warning" other than that posted by the site owners.
As to the American right of "Free Speech" we can very easily vote that right away without ever realizing it until it is too late. Certainly there is speech which forbidden (even in America). Examples, the classic is yelling "Fire" in a crowded theater. Another example is for Tree to post my real name and address and advocate that someone come to my house and rape me. (Make sure he's good looking and well hung Tree!)
But even today we are seeing things like "I HATE Martians!" being labeled as 'hate speech' and even judges (admittedly lower level) are ruling that isn't allowed.
I'm two generations removed but my mother lost cousins liberating Europe from the Nazis. I think the ideology is incredibly stupid and you'd be an ignoramus to adhere to it, but I don't have the right to say to someone "You can't read or quote "Mein Hampf" [sic]". While I am RC I have a Jewish great grandmother with all women between me and her. Since Judaism passes down the matriarchal line I could be Jewish by the rules.
Hell I'm Jewish and a lesbian, how fast do think I'd wind up in concentration camp as an 'undesirable'?
But I don't want a government (or society) that feels it can tell me I'm not allowed to be bi and into BDSM. But if I allow the government to control what you think and say (not ACT, acts can be criminalized) I've given them the right to come after me.
And let's face it we all know of politicians who want speech they don't agree with banned, no matter what side of the spectrum you are.
I won't live to see it, but I do have nieces and nephews, who if they write something like I wrote above out in the ether, it will be captured, analyzed and they will be punished. Maybe without even knowing it.
Let's face it, we are all here because we can't have crux conversations in the lunch room at work.
Sooner or later the morality police will come after me. And I will be branded with a 'Scarlet A' before I'm led to the stake for burning.
You're all welcome to watch.
kisses
willowfall