I'm sorry but there is absolutely no excuse for that type of behaviour. I never had to take a school bus, I don't know what she is meant to do as a monitor BUT as a human being there is no reason at all to be treated so horribly. The way the world has gone, I'm fairly certain her hands are tied regarding how to react to these little brats. If she kicked them off the bus? She'd most likely have one of the little rats lie to their parents, and the rest of the pack will follow up with the story and she will end up in trouble. It's a lose lose situation.
These kids were acting in a "gang" fashion, and to be frankly honest when I come across teens hanging around in groups, I put my head down and keep moving. She is in a situation that looks like she is completely lost on what to do, and very clearly upset. If she got up and made a big deal out of it, the kids will feel like they have won. Yes, I'm sure they are trained on how to deal with A unruly passanger, but a "gang" situation is a different kettle of fish altogether and is very daunting no matter the age.
We're all going to hear that little Jimmy's friends made him do it, or little Tommy is a good kid and that was not his voice we heard. We need to go back to the days where teachers could pull kids up and kids knew respect and had manners! It's about time parents got rid of the half hearted bold step and got out the wooden spoon and put the fear of god back into kids.
Stop for a minute, open your mind, learn. You may not agree with what I say, I may not agree with what you say but we will both learn something new.