What?! Are there such persons for real? I would not dream of touching another person pack without permission.
There are such around but usually they grow up. As young scouts we went on a camp near Ambleside, we were the younger scouts. Still, part way through the camp we got walked to Ambleside and let loose in small groups (like wild animal packs) with the money left with the leaders by our parents. Our group like pretty much all the groups went knife hunting. Back at the camp we played "see who could throw a knife nearest the other kids nether regions" while sat in a nice clearing just out of sight of camp.
As I said, most people like that grow up, like we all did by be the next camp, but the there's always the odd person with some form of what I suppose is a hidden disability. Someone for whom boundaries are kind of missing. I knew a very nice guy once who had a complete lack of I suppose you'd call it inhibitions. He was crazy! Actually two such people. One at school was looking into a park pond in school break when he decided to fall in completely flat. So he put his arms around the lads either side of him and toppled forward. One got away but the other ended up under the water with this guy. Asked why he simply thought it in would be fun. Asked if it was he said no because he's wet through. Lack of consequences in his mind? He ended up joining the army at 16 and became what I think was called a sapper working on explosives!!! Not bad for a guy who also got suspended for a week for letting of home-made explosive devices inside ancient, dry oak lockers in the basement of school.
Seriously, as kids it's common to see some kids getting into things that shouldn't. Some just don't grow up with the inhibitions that stop it as adults. There often fun to be around but you have to watch out too.