Brian Robertson was charged with a felony count of planning to cause serious bodily harm or death thanks to the story he wrote, Evacuation Orders [PDF].
The story described preparations for an armed invasion of his school that included directions to unnamed fellow commandos to kill the senior class principal and then plant plastic explosives around the campus. After searching Robertson's car and his parents' home, authorities found no weapons, traces of explosive material or any other evidence that the teen was planning to attack his school.
But authorities said the story Robertson wrote was sufficient to charge him under an Oklahoma state statute, which was passed in the wake of school shootings across the country in the last few years.
The full story is at Wired. There's also more Here, and Here.