Mark V Shaney is a synthetic Usenet user whose postings in the net.singles newsgroups were generated by Markov chain techniques, based on text from other postings. The username is a play on the words "Markov chain". Many readers were fooled into thinking that the quirky, sometimes uncannily topical posts were written by a real person.
Bruce Ellis did the code and Rob Pike did the design. Don P. Mitchell wrote the Markov chain code, demonstrating it to Rob and Bruce on the Tao Te Ching at first. They chose to apply it to the net.singles netnews group.