80%+ of some people's interaction with others is through a screen or keyboard. When they are faced with in-person interaction, they have no clue what to do. Being on a forum, you are going to get more of that. The crazy part is that people start to default to what they see on TV or in movies. They don't understand that stuff is fiction, not reality.
I don't think human interaction will deteriorate as far as Demolition Man, but tech is going to change some social norms.
There was a paper recently that suggested that latter half millenials, those born and raised in the iPad era have remarkably less empathy in certain situations than other generations and it is suggested that this is because a huge amount of non verbal communication is not being learned because of life spent behind a screen.