Every now and then, somebody in a movie will act so outrageous that random strangers will run up and start attacking them. They probably have no idea what's going on, but they know that it needs to stop. By force, if necessary.
It's definitely a good thing that we don't often see this happen in real life, but every now and then, we'll see some behavior that makes it easier to understand.
The problems we're about to see don't need to be solved with violence, but they definitely need to be solved.