Banned for turning your bed of nails upside down in the backyard in an attempt to skewer some pesky gophers.
Speaking of water balloons, a person I knew back in the 60's found a 12 pack of condoms. What he used to do is piddle in one, blow it up 'til quite large then let it loose above a group of people before bursting it with a blow gun, thus showering everyone below with pee. Yup, a dirty, dirty bastard.