I saw a grown man walking around a parking lot on the weekend transfixed to his phone. His behaviour/movement seemed odd. I said to my buddy, "do you think he is on Pokeman GO". My buddy thought about it for a moment, then the dude changed directions, backtracked, turned again and walked into a parked car. My buddy said "Yes"
The game seems pretty harmless to be as long as people don't completely lose situational awareness - which seems to be the problem.