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.