> It's already illegal to threaten journalists [in] America

Not necessarily, it depends on the pressure and the intent.

> In America we generally make bad things illegal, not activities that could become motivation for bad things.

I didn't mention making anything illegal. I suggested constraining Polymarket and similar.

> Should we ban [X]

I didn't mention banning anything.

>In America we generally make bad things illegal, not activities that could become motivation for bad things.

Not really, even in America. Like, take alcohol regulation. Your model would be "drunken bar fights are already illegal, so just prosecute that, problem solved."

Except that, historically, there's so much of that that it overwhelms the ability of law enforcement to keep up. So we try to remove the driving factors: "Okay, you can drink in public, but only[1] at these licensed places that are heavily incentivized to prevent fights before they start."

I'm not advocating any particular position, I'm just saying that if there's a persistent situation that heavily incentivizes violence, then it's not unreasonable to push back on that mechanism rather than just try to mop up the violence after the fact. Which specific situations merit that is up for debate, but it shouldn't be controversial that some situations should be handled this way.

[1] Yes, I'm simplifying, just focus on the general point here.