EVERYONE was,in one shape or another,bullied in school at least once,and would be lying to say otherwise. In my experience bullies get away with their criminal (Yes,it IS criminal. Every bully ever is chargable for harassment,at LEAST) activities is because of the impotency of the punishments,and the startling irregularity of them. After all,the best way to deter negative behaviour is the certainty of proportionately extreme retribution.
Why don't the victims do anything about it? Generally,they don't want the bully coming after them because they snitched. Why donesn't school administration do jack squat? Probably something to do with public image,so they just suspend the bully,essentialy handing them a sabbatical. If they're really bad,they get expelled,and cause bitter resentment in the bully because their life just got shafted HARD. Thus inspiring more bully-like behaviour.
However,usually it's just "Sit in the office,alone,during lunch hour." that half of the time,they don;t even show up for,and,beyond a paging or two,there is never any active effort made to bring the bully in to recieve punishment.
Bullying happens and can be stopped. However,it'll take a massive effort,and COMPLETE restructuring of how we punish n'er do-wells. Chocke hold a kid against the wall in the washrooms? Give them the full volume chewing out,lay charges immediately on first offense,no exceptions. Spreading false and defaming rumours about someone? Full volume riot act,and threaten to press charges if it continues.
Failing that...Get the switch. Sometimes,the only thing that will get through their mind that what they're doing is unacceptable is when the figures of authority inflict physical discomfort in response to repeated reprehensible behaviour.
Just my views on bullies and how the current society incubates them.