[wpietri]

Pssst: You do not live in a Hollywood movie or video game.

Here in the real world, he biggest recent terrorist incident in the US, the Boston Marathon bombing, used a backpack. But nobody is suggesting that kids be arrested for bringing backpacks to school.

And yes, the kid knew what he was doing: bringing in one of his hobby projects to show his teachers. Which is exactly what we want students to do. The problem is that the teachers didn't know what they were doing.