49ers fans think Seahawks fans were too loud
And as some 49ers fans see (or hear) it, they were too loud.
A letter was sent in to the San Francisco Chronicle complaining about the atmosphere. Written is that loud stadiums are equivalent to performance enhancing drugs and that the NFL could curb the noise by preventing home games from being played at stadiums that are deemed to be too loud.
And according to DeadSpin.com, the next day another letter, that agreed with the first, was sent in.
So there is that.