Gaming Networks, Virtual Worlds, and Other Technologies
Some of the most interesting online communities form around gaming networks (such as battle.net or Sierra On-Line) and virtual worlds (MUDs, MOOs, etc.). Each network has its own purpose, personality, and problems. Governance of such networks depends upon what problems must be addressed.
Gaming networks give gaming enthusiasts the opportunity to compete against more opponents than just their friends, and are quite popular. In a typical moment of a typical night, Battle.net (Blizzard Software's gaming network, featuring games such as StarCraft) has over 30,000 connected users playing in more than 9000 matches. Battle.net keeps users' win/loss records and features an ongoing competition among users; as a result, governance focuses on preventing and punishing cheating.
Punishing cheating on Battle.net usually means warnings from the company or deletion of a user's account (a dire punishment for someone with a record built over hundreds of games). 
Blizzard focuses more on preventing cheating, however. The tournament rules are constantly being updated as new methods of cheating appear , and the game software packages themselves are constantly patched for the same reason . If cheating is technologically impossible, no disciplinary action would be necessary.
Virtual worlds are more complex than gaming networks, however, and thus are essentially impossible to regulate automatically. According to the FAQ,
A MUD (Multiple User Dimension, Multiple User Dungeon, or Multiple User Dialogue) is a computer program which users can log into and explore. Each user takes control of a computerized persona/avatar/incarnation/character. You can walk around, chat with other characters, explore dangerous monster-infested areas, solve puzzles, and even create your very own rooms, descriptions and items. You can also get lost or confused if you jump right in... 
Governance in MUDs tends to be somewhat autocratic, with the owner/administrator of the MUD acting as the king. On LambdaMOO, for example, users vote on "laws" which are then added into the software "as soon as possible" by "the wizards," or the administrators of the MOO (an object-oriented MUD).
Vigilante justice could also be possible in a MUD, for users are capable of "killing" one another in some implementations. (According to the FAQ, multi-user games of Quake also count as MUDs....)
There are so many different ways to communicate on the Internet that it is impossible to cover them all. We have selected what we consider to be a representative sample of the various technologies available. To give an idea of what else is out there, we present the following list.