I'm not saying we should bury the lad for a tweet, but as adults we shouldn't be reinforcing the notion that that sort of nastiness is ever okay.
No one is saying it's OK. But advocating a punishment is hypocritical and not worthy of debate.
I don't want to live in a society where people are demonised in later life for very minor mistakes they made as kids. I heard and was guilty of plenty myself when I was 14, but it's called growing up and thankfully 99% of people do grow up.