/soo'doh/ (Usenet) Pseudonym.
1. An electronic-mail or Usenet persona adopted by a human for amusement value or as a means of avoiding negative repercussions of one's net.behaviour; a "nom de Usenet", often associated with forged postings designed to conceal message origins. Perhaps the best-known and funniest hoax of this type is BIFF.
2. Notionally, a flamage-generating AI program simulating a Usenet user. Many flamers have been accused of actually being such entities, despite the fact that no AI program of the required sophistication yet exists. However, in 1989 there was a famous series of forged postings that used a phrase-frequency-based travesty generator to simulate the styles of several well-known flamers; it was based on large samples of their back postings (compare Dissociated Press). A significant number of people were fooled by the forgeries, and the debate over their authenticity was settled only when the perpetrator came forward to publicly admit the hoax.