>One wrinkle in your argument - If the costs could be taken from parents, that would be great, however one group of bad actors in these situations is adults. So as a class, there is some case that could conceivably be made for adults to bear that cost.

"Bad actors"? I see three separate subsets of people, different unions of which would yield possible interpretations of "bad actors":

* Adults targeting children with the intent to commit illegal acts. E.g. groomers.

* Adults targeting children with the intent to commit legal but harmful acts. E.g. adults marketing lootboxes to children.

* Adults engaging exclusively with other adults in legal interactions that would be harmful (and possibly illegal) if a child were to be involved. E.g. adults trading pornography and banning minors on sight.

(Let me emphasize that these are mere examples, not necessarily representative of their set.)

I don't think it's in dispute that all three sets currently exist on the Internet. I would not say that the third one is a bad actor, though. Yet it by itself would be argument enough to either remove children from the Internet or to cordon them off to their own exclusive corner. So if the third set was the only one that was non-null we would have a situation where there are no bad actors, yet all adults are still bearing the cost of this system.

Now let's suppose that only the first set is non-null. If there's a bunch of criminals targeting children, that seems like a police matter. Why are law-abiding citizens getting roped in? En masse, at that.

For the second set, legislate until it becomes the first set.