The peroxide group is quite unstable as are the idiots who play with them; but they are not WMDs by any stretch of the imagination.
Recipes are all over the internet for all sorts of destructive devices that can be made from household chemicals, if the security net is stretched to cover this panopoly of possibilities, we will have already lost the reason for winning the war.
It's a matter of leverage. If several bombers get into a packed stadium, and visibly self-detonate minutes apart, they will trigger a panic stampede. The upper decks will turn into human avalanches going over the railings, as tens of thousands bold downward for the exit tunnels. The exit tunnels themselves will pile up with bodies as the faster go over the slower. It will be ugly.
Leverage. 20 times more will die in the panic stampede than from direct bomb effects.