Some good news from the Great Northwest of the U.S. More specifically the American Redoubt. You can have one gun for home defense... I'll have whatever this homeowner had. Seems to have worked well.
Not likely to be lethal, however, they can maim children. http://www.cnn.com/2014/05/30/us/georgia-toddler-injured-stun-grenade-drug-raid/index.html
Every type of Ordnance has the potential to be hazardous, a LAW, has a specific use and in the hands of an idiot, well you can imagine. We had a very specific way to use flash-bangs, as an alternative to killing people on entry, not to be used indiscriminately, tossing them into unknown quarters.