i used to do a similar thing with junkmail i received
fill the envelope with dead batteries and garlic paste and send!
(
Spunky McPunk not dead yet,
Wed 14 Apr 2010, 19:09,
archived)
I thought about that
But figured that anything considered as 'matter' might be considered more than mischief
(
mattyboy (slight return),
Wed 14 Apr 2010, 19:35,
archived)