I know this isn't going to be a popular opinion, but I don't buy into this.
Bullying is mean and cruel, but short of physical confrontation, I don't understand the commotion.
And "cyber" bullying? Give the authorities what information they need and move on. Running does nothing, but give the bully exactly what they were out to accomplish.
Somebody doesn't like you? So what? Who cares? Kids need to learn to worry about their lives, not what someone else feels about it. What happens when you daughters move on to college or the real world? Who is going to look out for their feelings then?
It is said that signs used to be held up at Georgetown basketball games that read "Patrick Ewing Can't Read This Sign". Seems to me that was more of an incentive than a detriment. Don't let them win. Keep going, live your own life and let them wallow in their misery.
Here's a thought. Getting nasty e-mails? Don't read them! Block the sender. Getting annoying phone calls or IM's? Give the info to the authorities and change your number. Yeah, you shouldn't have to, but what is your alternative, you're going to need to do it anyway.
But the priority here is to teach the children the irrelevance of the acts of the bullies.
JMHO