Not stop, I'm not naive. But the whole motivating factor for anyone doing the right thing is to, at a minimum, make some kind of a difference. If I could help my own children not be victims of bullying, and in turn they help a few of their peers to not be bullied, I'll put a mark in the win category.
To address Blacklabel's post about "war on bullying" and how "parents/kids can do more to prevent it," I can't help but come to the conclusion that you have very little experience in the world of bullying. If I'm wrong, please correct me, but I was bullied in school, and the guy's parents were d-bags, so nothing could be done on that end. As far as just "Standing up to the bully" that could have brought on more trouble as the kid (learned this later) was an absolute psycho and probably would have killed me had I stood up to him. Not to mention the fact that our "kinder, gentler" society does not allow any school violence of any kind- so sure, tell your kid the kick the snot out of the bully, and watch as they get punished too. Besides, I don't want to sound like a pacifist here, but I don't think giving a bully a beating will really help with some kids these days- it might lead to more, harsher, retaliatory action against the victim.
ETA: Jim's not a bully, I never considered him one, and, unless something changes, I don't think he'll ever be one- unless it's concerning nynco or someone like that. I like how Jim provides a different perspective, it add color to the conversation.