@ AMA: this is a simple case of "turning the other cheek" gone wrong.
Fowler could turn the other cheek to the situation and have his colleagues have their prayer. His colleagues could turn the other cheek and respect the moment of silence while still praying to themselves. His parents could turn the other cheek and accept the decision of their son, even if it doesn't match their beliefs.
The thing is, if Fowler turned the other cheek, he'd be an accomplice of an illegal activity (support of a specific religion by a public organization, which goes against the First Amendment), so he rather chose guaranteeing the legality of the graduation event.
So, what's the Christian response? Instead of listening to their own Messiah (Matthew 5:38-42; Luke 6:27-31), they harass him, threat him with death, publicly mock him and, the cherry on top of the cake, his parents disown him. None of this is illegal, but also none of this indicates that his peers have a good set of ethics.
Also, about "atheists being overzealous just because people mention God", you're mixing things up. I couldn't care less people talking about God, I even do it myself due to speech tradition, but there are places and contexts for it, and a graduation ceremony in a public school is not one of those places. If they wanted a prayer, they could just go somewhere else after the graduation and pray there. That way, those who don't want to pray can just skip it and everybody's happy, instead of causing a case of tyranny of the majority.
Also, about that little joke you made with banana, try to think what'd happen if the girl said this:
Our heavenly Ganesh, we come here today with thankfulness and a grateful heart for the friendships and the memories that you have given us as the class of 2011. Even though, for many of us, this’ll be the last time that we gather together as a class, we pray that you will lead us, guide us, and watch over us through all of our endeavors throughout the rest of our lives. In Ganesh' name I pray, amen.
I don't think she'd get any applauses from the Christ-aholic crowd.
Actually, goddamn. Looks like this school has a goddamn Bible study course, for fuck's sake.
I have a distinct feeling that Ezekiel 23:20 isn't in that course, I wonder why...