I don't think it's prevalent not at all, but there are a very small number of people who are genuinely addicted. I was watching this documentary on a Chinese internet addiction 'rehab' camp. Thought they were really overstating the addiction these kids had since they seemed more like introverts rather than genuinely addicted. There are bars on the windows, some of the kids spent the time to slowly apply saltwater to the bars to rust them enough to break them. The first thing they did when they escaped the place? Immediately go to an internet cafe and start playing videogames.