Yep that's what I'm saying... any other day it's normal to just sit wherever. But on a day where the game's sold out and I run the risk of someone kicking me out of their seats, I might as well sit in my own seats.
Plus, I did read somewhere (maybe on here) that there would be more security for this game and they'd be checking tickets at every section to make you sit in your assigned seats. Don't know if that's true or not but it sounds about right.