Our representatives. Our judicial system. Our public institutions. Our private businesses.

You're WAY too hung up on this "who decides?" question, ignoring the reality that either someone has to decide, or that no one should decide and society should simply not regulate speech in any way, ever.

Good luck with the latter if you ever have kids.

If we do get there, I hope we can ban the most dangerous speech of all - religion.

Ah, but the devil is in the details.

And you're still dodging the fundamental questions I asked you a while back. You're just playing devil's advocate in the details. It's a lame and boring argument.

All of the above, and more. Organizations like Facebook can decide to deplatform white nationalists, and we can vote with our clicks or whatever in response to that. You and I can get on message boards and advocate for what we think is just. Over time we all shape our society in our image.