Online discussion is a relatively new form of communication, facilitated usually by computer networks. The first such communications were on mainframe-based systems such as the PLATO and CONFER systems in the early to mid-1970s. By the mid-1980s, dial-up bulletin board systems or "BBS's" run by hobbyists on personal computers began to host online discussions, as well. As networks became more sophisticated, and access to said networks became easier (such as through universities and "dial-up" access), networks like USENET hosted an immense range of discussions. In the early 1990s, Internet Relay Chat became (and remains) popular. With the advent of the World wide web (WWW), myriad web forums have become new forums for discussion.
Online discussion groups tend to have a social element to them similar to a clique. There are generally established leaders (perhaps the owner of the medium the communication travels across), as well as more and less frequent communicators (or "posters"). Additionally, a discussion of the social properties of online discussion would not be complete without mention of the internet troll. These social networks can be very dynamic, can contain many thousands of members, and can even originate swarms such as the 1999 Seattle protests.