alt Hacker News> I don't really see how we've decided that anonymous porn isn't blatantly public indecency
That one seems pretty obvious. The point of public indecency laws is so that your family can go to McDonald's and not encounter some couple fornicating on the table. Whereas if you go to a private house where someone lives with a reputation for not being very selective about who they take their clothes off in front of, that's not a public establishment.
A privately owned PC connecting to a privately owned server is a private connection, not a public place. It's something you get by going there. You're not required to go to the frat house.
A private business that serves the general public is a public establishment though, even if it's run out of your home. The criteria is whether you restrict access to some private group, not whether it is a privately owned space. I'm not seeing how a server that responds to any traffic without any selectivity (KYC, basically) is not analogous.
It doesn't matter if you're not required to go to the frat house. It matters whether the frat house lets the public in while exhibiting their fornication, or has filters at the door.