Poor, innocent, hapless newbie wanders into a forum and wonders aloud if that guy in that show should be with that girl in that show. The forum erupts into flames, igniting all the boards that deal with the show, which ignites whole sections of the Internet into a blazing Inferno. The poor, innocent, hapless newbie has opened the door, causing an Internet Backdraft. This is also known as "Holy Wars". Trolls and Fan Dumb are drawn to to them like flies to a carcass. Mike Reed's Flame Warriors refers to this, when the metaphorical "door" is opened on purpose, as a Grenade.