Media and communication has evolved. Just how is sitting bored waiting for a subway car or bus more anti-social by using a smartphone/wireless tablet rather sitting in silence? How is that rude?

We have evolved to a more instant communication society, communicating by and through the Internet.

Using a Internet connected device in what should be a social setting; a sit down meal, some excursion with friends or family, in a theatre -- is the same as reading a newspaper years ago (e.g.; at a sit down meal) -- anti-social behavior showing a lack of interest in face-to-face interaction.

I fail to see the difference in the current context. What was rude is still rude only the "tool of the rudeness" differs.