"Internet addiction" seems like a different thing than the rest of those to me.
Being addicted to discovering new information and sharing with others sounds pretty healthy to me. I think the difference with HN vs FB is that at some level, you are driving your HN interaction, while FB is driving your FB interaction.
I think it only becomes "internet addiction" when you're not the one in control.
I was "addicted" to discovering new information before the internet existed. I biked 20 kilometers to the city to spend hours in the library and dig around in the shelves. When I got got access to the internet in the early 90s I spent hours to search in Usenet news and gopher sources (www hadn't been invented yet). I would not call that always a healthy behavior. It can be pretty inefficient and lacking any direction. Yeah, I sometimes wonder how narrow knowledge my fellow programmers or my early colleague from university who is a professor of computer science today can have.
My interaction on HN could be more focussed to learn something new and not comment something old...
Being addicted to discovering new information and sharing with others sounds pretty healthy to me. I think the difference with HN vs FB is that at some level, you are driving your HN interaction, while FB is driving your FB interaction.
I think it only becomes "internet addiction" when you're not the one in control.