Go read about the knife attack on van gogh or any other knife attack. When someone is crazy and wielding a knife, you back away. I forget which world class MMA fighter said it, but he said that if anyone approaches him with a knife, he'd run. That's a world class MMA fighter.
There was an interesting podcast on the guy who stabbed a kid on a bus in canada. As the guy was stabbing the kid, everyone on the bus fled. And then 3 guys got together and decided to board the bus and try to save the kid. When the three guys got back on the bus, the guy showed his knife to the 3 men and they all just left and waited for the police like everyone else.
Also, what's with a vocal minority on HN blaming anything and everything on smartphones and social media? I swear in the past few months, it feels like every HN story with a smartphone or social media angle is being targeted to push an agenda.
Edit: Found the podcast ( sword and scale ep 31 ). Really fascinating podcast and worth a listen if you have the time.
You are right that it is not about phones, it is about people.