[1] We also calculated Cohen's [[kappa]] as a measure of intercoder reliability, and relied on Landis and Koch's (1977) benchmarks for assessing the relative strength of agreement: Poor (< 0), Slight (.0 - .20), Fair (.21-.40), Moderate (.41 - .60), Substantial (.61 - 80), and Almost Perfect (.81 - 1.0). As we were involved in an exploratory analysis, we retained those coding categories that reached at least a Moderate level of agreement, eliminating others (see Table 1).

[2] 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.

[3] Names of newsgroups are shown in italics. Newsgroup/* indicates a hierarchical nesting of related newsgroups.

[4] For this coding, we restored to the coding scheme a few critical categories after removing previous ambiguities in meaning.

[5] 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.

[6] 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 [...]).