I was a group home parent for an American Children's Center. The kids at that center were all 12-18 years old and either juvenile delinquents or deserted by their parents. They were sent to the home we lived in (and the center paid for) as a reward for being relatively good for a short period of time or for not deserving to be in that center at all. Two of the boys we had landed there because their parents declared they were damaged goods -- one kid was adopted with his brother by a woman who lived 1000 miles from the adoption center, and that kid was dumped off because, at the ripe old age of 7, he couldn't keep still during that 1000 mile drive and then had the audacity to push his mother away after she hit his penis repeatedly with a ruler and she fell into a glass top coffee table. (He lived with the guilt, and she thought she proved her point that something was wrong with him.) The other kid got the words "saw" and "was" mixed up in kindergarten, so his mother was sure he had dyslexia making him damaged goods. (Everyone of my siblings and I got mixed up with those two words. Only one of us has dyslexia.) The rest of them were so beyond control, their parents couldn't deal with them. One was out and out dangerous to the point he raped a little neighborhood girl while under our care.
Matter of fact, that was why we quit that job, because the Center told us to keep quiet about it or we'd be sued. (I did tell a judge later when they asked me if that boy should be emancipated.)
The psychiatrist at that center taught all the boys that their actions had everything to do with peer pressure. The boys used that, until we asked them what peer pressure meant. None of them knew.
The counselors, who were really there as enforcers, and, as you can now imagine, were needed as enforcers, were hired for their size and strength. The "little guy" was only 5'10" and 240 pounds. Their job was to body slam the kids when needed. They also taught the difference between what was acceptable and what wasn't. What wasn't should never be done around them, or they had to stop it. What wasn't acceptable was to attack troublemakers with large bars of soup wrapped in a long sock and used as a whip to punish any child after the counselors withheld privileges on all the kids for the one child that did something wrong. Yeah, I mean the counselors taught the kids the trick with the soap in the sock before telling them not to do that after they were punished for what that child did.
And the kids listened. They waited for the counselor to leave before they got the soap and socks out and did just that. The boy was bruised from head to toe. And that boy was as sweet and innocent as that boy in the video throwing metal furniture at the window to try to get out.
So, you're going to suggest guns would have solved Australia's problems like we've solved ours? You don't even have a clue we HAVEN'T solved our problems. Making sure you don't know what happens inside the foster care system is a grand way of avoiding solving the problem!
I hope you don't have a gun, because clearly you aren't responsible enough to own one.