You have to be aware that it can happen, it is out there somewhere, but you can't live your life worrying about it. If they think they can talk about stuff, they won't keep it inside, and it won't build up as much as it has in some of these kids. If someone you know is having a rough time, go up and talk to them. Don't just say it once. Talk to the kid.
Students impact is far greater than anything coming from a parent.
There is a small percentage of students who do care. Encourage them to voice their opinion, and they will.