A lot of the Commonwealth states, along with Britain itself, have the attitude of "If it's abused once, ban it." That's why Australia banned body armor, and Canada banned the Mini-14 specifically. In the latter case, someone did a mass shooting with one. Despite the fact that there's other semi-auto rifles available, Canada specifically banned that rifle.
Body armor is legal here in the US, despite fear-mongerers' claims that "body armor will soon be banned". The people who say that are just trying to scare you into buying their product. Level 2 body armor will protect you from almost all pistol rounds, with the exception of some oddball calibers like 7.62 Tokarev (small-caliber, high-velocity). Even .44 Magnum will be stopped, though it'll still leave a mark. Keep in mind, though, that you have to go up to Level 3 in order to have any protection against rifles.