A cooperative study from the University of Bath, UK, and Texas A&M University found that people who walked and texted while navigating an obstacle course walked more slowly than when just walking. They also slowed down if distracted with a math problem while walking and texting.
This episode underlined the hazards of texting while walking, which can surely be as dangerous as texting while doing almost anything else. Almost: there are no available statistics on the adverse effects of texting while having sex, which seems popular in some demographics.
This is not a blog on your rights. You have a right to be oblivious to your surroundings and a right to be obnoxious. That includes your right to obnoxiously use your smartphone the same way you obnoxiously do anything else. This is a piece on etiquette.