Yes, he needs to apologize now and made to realize that what he
did was wrong.
Otherwise, he might grow up thinking that it's right to make
these comments.
You don't charge a kid with a crime, but you will still have to
discipline him when he's out of line.
Mind you, people have been arrested all over the world for
making bomb and murder threats on social networks. Go read it
up.
I'd rather have him be talked sternly to now as a kid than be
thrown into jail later on as an adult.
Very well said.