This person has obviously never listened to FOB: they don't scream at all.

well, if what she means by scream is screamo/death metalish kinds of screaming, then yes, tehy actually have done that before. Not an actual screamo/death metal song, but if you listen to From Under The Cork Tree, Infinity On High, and Folie a Deux, you'll notice that Pete screams quite a lot.
(there's even one song on Cork Tree where Patrick screams too!)

im such a fob nerd

Well Calm Before The Storm on Take This To Your Grave has screaming in it, there's a very small part on The Patron Saint of Liars and Fakes, and there's some in From Under The Cork Tree, Infinity On High, and Folie à Deux and probably on the E.P. and on more of tttyg but a person that doesn't like Fall Out Boy is not a person I wanna know lol

Aww, come on... Pete’s screaming in pre-hiatus songs is awesome!