dogpile

v. [Usenet: prob. fr. mainstream puppy pile ] When many people post
unfriendly responses in short order to a single posting, they are sometimes
said to dogpile or dogpile on the person to whom they're responding. For
example, when a religious missionary posts a simplistic appeal to
alt.atheism , he can expect to be dogpiled. It has been suggested that this
derives from U.S. football slang for a tackle involving three or more
people; among hackers, it seems at least as likely to derive from an
autobiographical Bugs Bunny cartoon in which a gang of attacking canines
actually yells Dogpile on the rabbit!.