[alephzer0]

This makes me so mad.
The fact that this kind of thread even needs to exist makes me lose confidence in humanity. FIRST is supposed to be an organization where kids can learn about technology in a friendly environment.
My advice:
There are multiple things you can do. In many states, there are strong anti-bullying laws that call for intense investigation at even the slightest hint of bullying.I don't know what state you're in, but do some research. If you can, file a report to the school. In many states, the police may get involved, and the people you accuse of bullying will be investigated. This will serve as a huge deterrent for future potential bullies.
If you have video evidence, make it public on social media; try to get attention elsewhere. If you get enough attention to the cause, you can find more advice. And as it was said earlier, once you post the videos they're public; you can use them as evidence in bullying investigations.
If all else fails, go for the throat. (Not literally. Please don't actually kill anyone). What I mean is report all this to the administration. If they disband the team, then start a new team somewhere else. But request that they simply reassign the team to a new teacher who will clean it up, rather than disbanding it.
Just remember: NEVER GIVE UP. Try EVERYTHING and then try it again. Something is bound to work.
NOTE: THIS IS MY PERSONAL OPINION, AND I AM ENTITLED TO IT. YOU CAN FOLLOW THIS ADVICE OR COMPLETELY DISREGARD IT.
Also, I am also open to be PM'd about this. I want to help as much as I can.