I was referring to an upvoted (at the time) comment calling for public shaming.

Would you also object if I said (which I am not saying, just asking hypothetically) that I suggest the public shaming only for the downvotes that will happen in the future, after this rule is agreed upon? In other words, is retroactivity your true rejection?

I consider the retroactivity not a good rule for a website, because a creative person can find more behaviors that are obviously wrong, but still not forbidden yet. For example, is there an official rule against hacking the server and deleting someone else's account? (Or, as an extreme example, finding the other user in real life and hurting them?) If someone did it, would it be okay to defend them saying: "well, it wasn't said explicitly that such behavior is forbidden, therefore we should protect their privacy"?

Retroactivity and similar rules are made for countries, which have more time and resources to debug the laws, more power to apply, et cetera. LW is not a country, it does not have to follow the same rules.