"It was, along with the traitor Peter Pettigrew, though he was mostly a bystander. Headmaster Snape was one of their biggest targets because he just seemed to "look evil', whereas I was bullied and harassed by the Weasleys because I fancied witches. As you can assume, once Severus was being constantly attacked by two or three Gryffindors at once, he retaliated with stronger hexes and curses, exacerbating the situation and dividing us in ways we couldn't even fathom at the time. Life is more than just Good Guys vs. Death Eaters, so when someone decides to call you a name, or laugh at your misfortune, stop and think if it's a good idea to whip out your wand.