A total of 438 e-mail messages were exchanged, but the other 215 e-mail messages dealt with the physical computer network rather than the news-system itself.
 Names of newsgroups are shown in italics. Newsgroup/* indicates a hierarchical nesting of related newsgroups.
 For this coding, we restored to the coding scheme a few critical categories after removing previous ambiguities in meaning.
 We use the term "opportunistic" not in the specialized sense used in economic analysis, but in the common language sense of taking advantage of an opportunity as it arises.
 All messages and some interview quotes cited in this paper have been translated from Japanese. All identifying and confidential information has been disguised or removed (indicated by [...]).