The Associated Press, in a story carried by USATODAY.com, reports that a Michigan teen-ager was arrested on Friday after he made online threats against his high school and its students. Police discovered that Andrew Osantowski, 17, had hoarded weapons and bomb-making paraphernalia in his home. Osantowski’s threats against his school were made in an online chat room, where they were discovered by the daughter of a state police officer in Washington state.