That's a pretty interesting though, never thought of it that way. Makes sense that the more things you can talk about, the less shock value they can extract from it.

From another perspective you could say they're lowering the bar overall, and you're saying the only way to deal with them is that you de-sensitize yourself to them. Nietzsche springs to mind, about gazing into abysses and battling monsters.

Is this a conjecture or a claim? In my experience the Overton Window is wider in the US than most other places, but there is also a greater tendency towards trolling in US society as well. These assertions would be challenging to measure, but might be amenable to proxy representations.

It's just my own observation. It's definitely wider in the US than other places but also enforced differently, depending on where you go. In the US, we have a "soft" enforcement, although with doxxing, etc., it's not so soft in many cases.