I love a prank as much as the next person but you can easily see how invasive, alarming potentially destructive this one is.
Somewhere, sometime the wrong cadre of personalities will react with a hail of gardening stones, bricks, glass bottles or whatever's handy to join in the fun.
Then it'll be your turn to jump and their's to laugh. Just predicting, Kira
ps Where do I get a set of those babies? k