Quiet and b***hing fans should stay at home. Stadiums are places that SHOULD be a bit raucous, this isn't a play or an effin movie. It's seats to the NFL war zone. If you go to the game, you should be excited and cheering when big plays are made and should revel in the excitement of your Niners brethren.
For you loud folks, when those old bags telling you to sit down or be quite sit on their hands during a big play, instead of cheering immediately stand up turn around and yell at them to stand up and be loud, all while staring them down like they are some unruly scum.