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!”.