I come to you in a time of dire need (Glam question)

[Midareyukki]

If you are not invited to an Apartment, then you stay out if the Owner is online and in his Apartment.
Feel free to look at open Apartments when the Owner is offline or in a different Area. That's what normal Players do.

Not really. People walk into houses, apartments and FC rooms all the time, regardless of whether the person is online or not. If you're so against it, lock it, otherwise you'll always be in such a danger of people walking into you doing something you don't want them to see.

Not to mention, the person called him by name. They likely knew them. And at no point did they tell him to leave in such a rude manner, nor did he overstay his welcome.

You're virtue signaling. Hard.

Yeah, it was bad of him to not censor peoples' names entirely, it was a gaffe and he admitted to it. One I unfortunately share. And both of us corrected it, he took the images down, I deleted the post.
But there's nothing illegal about what he did whatsoever.
Preach privacy all you want, if you wanted privacy, you should have taken the steps to do so.