Cool -- Wikipedia teachez
On a lark read about the AR-15: http://en.wikipedia.org/wiki/AR-15
Took me to this: http://en.wikipedia.org/wiki/Port_Arthur_massacre_(Australia)
Which took me here: http://en.wikipedia.org/wiki/Martin_Bryant
The lesson: powerful guns shouldn't be available to demented people, and maybe shouldn't be available to people at all!