Source : Free On-Line Dictionary of Computing

Cancelmoose
     
         A semi-mythical being that cancels {Usenet}
        {articles} posted by others.  (In general, an article can only
        be cancelled by its original author.)
     
        The Cancelmoose's usual target is {spam} or extremely
        excessive {cross-post}ing.
     
        Some believe that the Cancelmoose exists only in the same
        mythic sense that {B1FF}, the {NSA line eater} and {Shub
        Internet} exist; others consider Cancelmoose's historicity to
        be closer to that of {Kibo}.  The latter group assume that the
        real Cancelmoose is not one person (or moose), but instead is
        a cabal of {NNTP} wonks.  However, the Cancelmoose is probably
        real, seeing as how it has its own {web site}.
     
        {Home (http://www.nocem.org/)}.
     
        (1999-01-14)