A few years back (
1997 or
1998 I think), some
engineers at
Queen's University designed and built a
potato gun. This was not
remarkable in and of itself, as this is the sort of thing that happens when
design prowess is coupled with
boredom in a
higher education setting.
When they fired the device, it apparently blasted the potato through a neighbour's fence. Minor damage, I imagine. However, the gun's booming report was mistaken by one of their neighbours for a shotgun blast, and shortly thereafter, the SWAT team raided their house.
I don't believe any charges were laid, but I suspect the "weapon" was confiscated.
(Source: the Queen's Journal, via my dim memory)