Are you both serious??? Those kids casually talked about her raping them and them stabbing her as easily as we talk about the weather. To an adult. To an elderly adult. They had no shame or guilt about it. They were PROUD of what they did and posted it on the internet to show off their bullying. Those kids, left on their own, were well on their way to be sociopaths and criminals.
The punishment is basically to go to a different school that is more strict and involves the parents more. They might not like it but there is no way it's overreacting.
And how do you know that? Do you have several years of history about how each of these kids have behaved in school and on the bus, and toward authority figures in general?
If these kids had a history of disruptive and disrespectful behavior toward authority figures or other students associated with the school system, them this punishment might have been justified. But I've seen no mention of any pattern of bad behavior.
For this one incident, no matter how emotional some are over the video and other circumstances, the school officials still used bad judgment and the punishment is too severe.
I said two or three weeks suspension and 40 hours of community service. That's pretty severe punishment for one incident of verbal abuse.
And since all the kids received the same punishment, it seems likely it was for only this one incident.