Do you really want the Govt controlling an Internet filter?
I definitely don’t think we should go the other way and legalize kiddie porn like pervertland Japan
The First Amendment relates primarily to political and intellectual liberty: it is the expression of meaning. It is a cognitive process: the conveying of ideas by speech and by the publishing (in today's world, the media.)
But porn, by definition, doesn't work because it "means something" (on the cognitive level); it works because it "does something." I don't think it's any exaggeration to say it's operant behavior conditioning, based on chemicals, brain hormones.
To put it simply (especially for you, my well-loved Laz), sexual arousal and release works like a drug because it triggers feel-good brain chemicals: it suppresses cortisol, sends in a rush of serotonin, dopamine, and oxytocin.
If you could get this stuff via a needle in the vein by pressing the S-E-X keys on the compute keyboard, you'd be reacting not to the cognitive meaing of word "sex," but by the entry of blood-borne drugs into the brain.
I think that's what makes porn different from "speech" and "the press." It has more similarities with drugs and addiction. In other words, it's not, precisely speaking, communication (an intellectual process). It's more like a chemical hit.
True, you could bring this on by plain-old masturbating with a tintype of Queen Victoria (if that's your taste.) But internet porn, especially, has a degree of instantaneous access, sensory overload, and perversion so extreme, that it compares to making IV heroin available to every 12-year-old with an internet connection.
It also sets up adult men to be interested in those 12-year-olds, because it significantly weakens their natural sense of good-touch and body-boundary, and their normal, self-protective aversion toward anything that is dangerous or perverted.
And that is a legitimate human rights and public safety concern.
(And citizen usa, it's obviously different from medical journals, art, and the like. Anatomy charts and Michelangelo's David don't reach right in from your eyes to your crotch to effect chemical-based operant conditioning on your brain.)
However, just as there may be legitimate criteria to distinguish between "active terrorist conspiracy" and political speech, and there may also be legitimate criteria to distinguish between "toxic BDSM pornography" and intellectual/artistic expression.
I myself, have had the experience of both being frustrated by a self-installed filter on my computer when researching a sexual issue, AND to have been assaulted by a sadistic image of sexual brutality which popped up when I was looking for an illustration for Louisa May ALcott's "Little Women."
It's not safe for me that men are being repetitively conditioned toward the torture of women as a form of entertainment. Or women so abusing men, or other women. Or children.
Keywords "Little women". No joke.
In a democratic republic, it has been possible to make such distinctions in the past, and may be possible to make them again.