What kind of moron would do that to another person?
Someone that's bored and thinks it's funny. They may be morons, but ask yourself, who's the one being stuffed in the locker?
Doesn't say much about their parents or their upbringing.
There's always someone to blame, whether it be bad parents, a bad childhood, abuse etc.
Maybe it was just the kids fault. Some children can be extremely rebellious and violent.
Children learn at an early age what is right and what is wrong.
A lot of that is opinionated. For instance, some children are taught that racism is right, because is in their parents' mind, it is right.
Some kids are taught not to lie because that's wrong, when really, lying can be the right thing to do at times.
It's all perspective.
(I have a little brother who is not much older than you and he is perpetually tormented by some really evil, vicious kids at his school. I wish I had some good advice to give him.)
Taking self-defense or martial arts always helps with physical bullies.
If the kids are physically harming him, it may be the most effective choice. If he can defend himself well, the kids will leave him alone.
For instance, one time two of them during a band party recently came up behind me and threw me into the swimming pool...
I assume you live in the suburbs?
A lot of inner city band members are tough, and usually people that are willing to fight you. The same with some large competitive University bands.
I remember seeing a sports show in which a band member was purposely run over by an opposing team's football player because he was on the field within the last seconds of play (the game was basically over), but the opposing team made like a 95 yard kick return.
In which one of the hosts said, "If they pulled that on my old Universities band members, he would have had his a$$ kicked." In which clips were shown of band members fighting each other.
In some places, band members are not to be screwed with.
They are probably full of testosterone and are looking for a fight, best to avoid those type of situations. I know people say that its better to face the situation rather than run, but in this case, its only high school and its not like these people will give you problems in the future.
Hmm...I've had older students threaten to hurt me before.
For example, a long time ago, I'd be in class, talking to my friends, then they'd all of a sudden an idiot would cut in, insult me and tell me they'd punch me if I talked again. Just out of nowhere, they'd do this. I figured he was drunk...or high.
He never talked me like that again after I told him that I just finished winning a Tae Kwon Do tournament, and if he really wanted to fight - then fine. He looked at me, then turned away. They always pick on the weak.
Thanks for your advice. I am so-o-o-o glad this is my bro's last year of high school.
Senior year can be the roughest. The students are older and larger.
I'd hate to imagine how badly one is treated during Senior year.
Think about self-defense. Judo is an extremely effective form of defense that usually won't harm the victim, aside from a few welts and maybe a bruised ego. An example: Motai knew Judo to the intermediate level, and some football player tried to grab him and throw him in a pool, he could have easily countered at the "grab" part, and slammed the moron right into the water.
Of course, there is always a chance that the Martial Artist gets over-confident and then, seeks fights. But that's rare.
Ha ha! 
I wish I had some good advice to give him.)