Sort of.
I am making an assumption that there are some people who are likely highly motivated to take action. Parents often care about bullying of their own children, even when the rest of the school doesn't. We wouldn't need all parents to care, just a few of them.
I'm not assuming that lawyers are generally willing to work for free but I do assume that they like money and are willing to take cases on contingency, if they think the case is strong enough.
I'm also going on my understanding that video evidence tends to be fairly strong and that this translates into a higher probability of a favorable judgement with less work on the lawyer's part.
So it's less that I'm making an assumption than that I'm asking where the gap in the above reasoning chain lies.
It would be pretty messed up if the punishment came before the crime.
My point, in this case is that the crime has been ongoing. Bullying and harassment aren't new. What's new is that we now have a lot of it recorded. This gives us an unprecedented ability to prosecute a class of crimes that people have been committing with impunity.
The biggest downside is that it would likely be short-lived. If there were a bunch of headlines about people getting giant civil judgements, bullies would probably learn to be more careful about generating evidence of their crimes.
That would likely initially focus on attempting to hide the videos from the general public but I suspect they would eventually learn that doesn't work; courts can compel discovery. They would probably also try to modify their on-screen behavior so it doesn't technically qualify as a crime but I expect they would mostly fail at that.
That said there would likely always be some cohort of dumb criminals who continue to record their misdeeds. We still see cases where people discuss their crimes over unencrypted email and we still see cases of criminals taking selfies with their crimes