Back to school woes

Autumn break is over, and many children are going to return to school on Monday with a feeling of dread in the pit of their stomach. Why?
According to recent statistics 'Mobbing', a (German) term coined for bullying or harassing, is on the rise at secondary schools, particularly in small towns.
Some of the pupils that I tutor have confided the most appalling things happening at their school, mostly same-age kids harassing a pre-chosen 'victim' of the day. Certainly, bullying has existed for decades, and I'm sure almost everyone has at one point during their teens been harassed or has witnessed others being harassed- perhaps even participated?
There is bugging and there is bullying - where do you draw the line?
When I was 14, I was 'the victim' of twins (girls), a year older, who bullied me regularly. It started with name calling (relatively harmless), then some pretty ferocious backbiting (not so easy to handle), to physical aggression, such as pushing me down the stairs etc.
Luckily I had, and still have, wonderfully supportive parents, who, after this last episode, thankfully arranged for me to change classes. After all, I was in danger of becoming seriously traumatized. Or I could have become aggressive myself - not a good trait later in life. And this really is the crux of the matter. No child is born vindictive. A child may have a predisposition to aggression, which if left unnoticed will become deeply ingrained in its character and will be the cause of much heartache as the child grows up.
But many parents are unaware of their child displaying such aggressive behaviour. In boys it's even encouraged to a certain extent!
A while ago I was talking to one of my pupils, a boy aged 15. The conversation went something like this:

me: So...how was school today?

boy: (shrugs) Hm.

me: everything okay?

boy: hm. yeah. teacher was sick today (chuckles)...got a B- in Maths (smiles dreamily)...a guy in my class got beaten up today (more chuckling)...
Hey, do you have candy?

I think this brief conversation speaks volumes, doesn't it?