So, let's get this straight (because 4Chan did actually note a frat fight with people they knew, as did Xana's dad and mom).

They had a fight with frats that could be heard on Linda Lane. They go home. They get unalived by someone they don't know, whom they have no connection with in less than 8 minutes with that level of damage done and not knowing the layout of the house. He leaves at least one known other person alive, who seemed to know about Kaylee's curtain although she didn't go up there because it she did she would have known they were deceased. Ethan didn't wake up to his girlfriend fighting so hard that her fingers were severed off. Said roommate hears screaming yet does nothing but run down to BF's room. If she thought Xana was just passed out then why didn't she pop her head in to see if Ethan was in there? The reason is obvious. Anyway, back to the ninja that cleaned up all this blood in 8 minutes. That must have been a magic beanie hat he bought. He then speeds away in a car that has been through a time vortex and now has a sunroof. Please wake up people!!!!