The Pats fans in my section (139) were from Boston and were pretty loud and unruly. There was an especially obnoxious one in the row right behind us who spoke with a deep Boston accent. Near the end of the game, when the Pats were driving, he was yelling "We're mawchin!" (i.e. We're marching.) He also was nice enough to thank us for the "free yards and free points" and kept yelling at various Bills fans wearing jerseys - "so and so sucks!" (such as "Milloy sucks" and "Clements sucks" etc.) I was hoping for him to get ejected but no such luck.
The endzone near me also seemed to be completely filled with Pats fans. I saw 3 ejections of Pats fans including a girl who was in people's faces and her boyfriend. There were also a few Bills fans ejected in the area. Also towards the end of the game, the Pats fans in the endzone section started chanting Bledsoe's name in a taunt. I'm not a Bledsoe apologist but I thought that was especially classless of the Pats fans considering the way he left the Pats.
I think Pats fans are growing especially intolerable because they think their team is invincible and as others have pointed out - most have only joined the bandwagon recently.