I realize this is an old thread, but thought I'd necro to add my thoughts. The apparently rampant bullying problem has come up a lot lately in my circles and like the OP, I think a lot of the apparent increasing frequency has to do with the redefining of what it means to bully. In conversations I have stated people with more social control must rebuke bullies for their bad behaviour; the rejoinder I often get is "but you can't bully them back". But shaming someone for bad behaviour isn't bullying. It's a way of laying down the ground rules for the group culture. And if it's not allowed, well no wonder no one knows how to act appropriately.
However I think that brings us to a bigger root problem. Rebuke is seen as "bullying" because it's negative and "not nice". I think a lot of these problems stem not from the fact that we're meaner but from the fact that North American culture has elevated an insipid "niceness" to the supreme virtue.
A friend once told me "niceness is just kindness minus any honesty." That's the rub I think. Kindness is a virtue. Nicety is an empty facsimile of it that has been stripped of all realness and truth. Kindness refers to being gentle and considerate while niceness has the connotation of being "agreeable". So while kindness is honest, nicety requires a lot of dishonesty and pretense. A direct and blunt person may be kind, but is never nice.
Yet we confuse the two and want people to be nice all the time (this can also be seen in debates where people assume everyone who disagrees with them is mean and a h8r. Really they're just not playing nice.). In reality they are very different and produce very different sorts of behaviour.
In addition, Kindness is directed outward in concern for others, while niceness is always self directed. For example, the kind person will rebuke or disagree with others because his concern for the other is greater than his concern about whether that person likes him or is a friend. These people disagree with you because they want you to get better at what you're doing--if that means you get angry at them, so be it. Yes they try to handle conflict in a gentle manner, but they don't back away from it if it means a better outcome.
On the other hand, the nice person will just let you continue on, try to "get along", never say anything negative or "mean" and hope everyone likes him--these people care about themselves and their image more than they care about you. The side effect of this is that all negative emotions to go underground which creates a culture where they are expressed in increasingly passive aggressive ways. The "nice" person won't tell YOU what you're doing is wrong, but he will tell everyone else. And as this behaviour is rewarded and accepted, it becomes more and more entrenched. The perpetrator can then claim "but I've always been nice to her" even if they've been targeting you with passive aggressive obstruction for months.
I've noticed that people often say "bullying" of this passive aggressive type is one of the pitfalls of a female dominated profession and to an extent I agree with that. I do think that's going to change in the next number of years, because the reason this behaviour is more common amongst females is that they have always been enculturated to be "nice" while men have been enculturated to be direct. This is changing and now everyone is expected to play nice all the time, both male and female. Make no mistake, it has nothing to do with sex and everything to do with gender education. As a woman who is not and has never been nice, I have definitely seen the repercussions of going against the norm.
Not surprisingly I think the antidote to niceness is kindness. The PA behaviour needs to be handled directly and honestly, with gentleness and consideration. But it must be handled and boundaries must be set, understanding that avoiding the problem (whatever it may be) only perpetuates it.