Some of us carry our own protection legally.
The case in Belgium was with young children.
The young fellow in Canada that got beheaded and snacked upon was asleep on the bus when it happened.
It does not matter what you might carry, packing a pistol might not mean much.
Crazies have guns too.
Remember Charles Whitman?
http://www.trutv.com/library/crime/notorious_murders/mass/whitman/index_1.html