I work downtown Chicago, and I constantly encounter this on the streets -- people staring at their phones, not watching where they are going. When they approach me on my side of the sidewalk, staring down at their damn white iPhones, I intentionally slam into them extra hard and tell them to watch where they're going. It's fun.
Bonus points if they're tourists.
That's a great way to get your face beaten in. Yeah, people gazing into their phones as they aimlessly shuffle about is irritating, but it's no excuse to be a misanthropic, obnoxiously confrontational dickhead.