Bullying is not assult, it's intimidation and harrasment, sometimes to the point of mental torture (especially for children and teens), people are not complaining about random insults from random trolls they are complaining that real life bullying is extended to online harrasment. The online bullies are KNOWN to the victim, there is no way for the victim to escape their attention in RL or online.
Anyone who thinks an insult is the same as a punch, has never had to deal with a real bully.
I went to school in the 60's, throughout grade school there was a girl in my level called Allison. Nature had not been kind to Allison and her parents often sent her to school in dirty clothes and oily hair. For her entire time at grade school the entire school would not go near here, at lunch time, after school, and on the weekends, the other kids would taunt her with chants of "Allison's germs". I cannot recall a single instance of physical violence against her but it is by far the worst and longest case of bullying I have ever personally encountered and I'm ashamed to say I participated willingly.
OTOH, I was punched a few times by "big bullies" myself, virtually all male children are at some stage the victim of a random bully, that is almost trivial compared to the constant mental torture Allison had to deal with in her childhood. We don't have any silver bullets for "cyber bulling" precisely because it's a continuation of what people (in particular kids) have been doing since before the dead sea was sick.