You hear different things depending on who you listen to as to who is causing the ruck, which leads me to conclude that both are equally responsible because they can't behave.
It's not about staying quiet, it's about staying rational. You can be loud without being hysterical
People blaming the fans are irrational, People who scream at other fans who say they don't like their banners are hysterical
The stewards taking banners from fans needs looking into it, as they seems to be a gross overreaction. But then my problem is not the message but the messengers themselves.....