I was expelled one time because they inspected my locker and found such a ridiculous hoarde of rule breaking items it seemed like a joke. There were 2 road flares, a pack of razor blades, various pocket knives, a Hustler magazine, a box cutter, a pack of cigarettes, 3 lighters, nunchakus and some fireworks. It was a religious school, so they also weren't too thrilled about the death metal cds, Satanic bible, Necronomicon, or hooded cloak and skull mask. There was also a roll of money and a zip lock bag full of oregano (that yielded some hilarious results).
Luckily this was pre Columbine hysteria or I probably would have went to jail, but it was pretty funny. I still have the letter they gave my parents with each item they found meticulously inventoried.