http://www.slate.com/articles/technology/technology/2015/06/texting_etiquette_the_fellow_blocking_the_entrance_to_the_subway_so_he_can.html

An affliction has come to the streets of America. Men of good health stoop and squint on the sidewalk. The stride of people with purpose shortens to a shuffle. They halt as if an invisible hand is holding on to their belt loop. People of no obvious malady and with no premeditated scheme of malice stop at the top of escalators, the bottom of stairways, after passing through a bustling public exit, and always in just the spot where they can most effectively clog a crowded street, causing mayhem.