pfft. the old fart over reacted. the kids phone was NOT going to cause the plane to crash. he had no right to take the phone or touch him.
though the kids parents (and the kid) are assholes and should have some respect for people.
And you know this because of your Engineering degree or your frequent flyer mileage?
When the pilot tells me to shut off my laptop or PDA, I do it even if I know it's not going to cause any issue.
They are the LAW on the flight.
That said, if there are others not following suit, I'd expect the PEOPLE to thwart it.
I am not going to beat down some kid unless he hits me first and even then I am just going to subdue them, not pummell them into a pulp.
However, if that kid did not acknowledge my request nor his parent(s); I'd smash his device no doubt about it.
I'd make sure to gather witnesses and get statements on the spot from some future lawsuit from the piss-poor parents now looking to make a buck.