Home made shuriken.
When I was a young teen taking metal shop class, someone got the idea of using the notcher to cut chunks of scrap steel plate into little jagged sunbursts that could then be thrown to stick into the ceilings, high on the walls, and other places where they would be deemed obnoxious. I saw one made by someone else, then made my own little supply of them.

If you make them fairly small and light, when they hit they won't penetrate very far and will come out pretty easily. And if you tape a firecracker to them, the explosion will be enough to knock them free.

Imagine being asleep in bed when an explosion goes off just outside your bedroom window, and the next day you can't find any evidence of what caused it...
( Wanderer, Thu 7 Oct 2010, 15:06, 1 reply)

i nearly got expelled in my third year of secondary school for this
i made one, was decking it into the back of the toilet door, when the class bully came in and releived me of it. he then threw it into a first year kid's leg at lunch. naturally he blamed me, and i got bollocked something rotten.
joke's on him though, he got sent down for keeping watch while his equally delightful northern accomplice robbed an old man's flat, pausing only to stab aforesaid old man in the head with a screwdriver, killing him.
(UppityDamnPrimate LET'S OPEN THIS F*CKING PIT UP, Thu 7 Oct 2010, 15:21, closed)