Responding to the previous presentations, Brian Fitzgerald and Nic Suzor now outline some of the legal issues involved here - games users' rights are governed generally by end-user licence agreements (EULAs), and these go right to the heart of the question here: in buying a game, does one buy a copy of the game, or a licence to use it? This then influences whether players own the content created in their interaction with the game. Indeed, the nature of the EULA may also influence what players are attracted to these games types.
Some legal cases of note here: in Blizzard vs bnetd, a group of players developed a replacement game server system for the Blizzard product Battle.net. While this is reverse engineering and prohibited by the EULA, reverse engineering is seen as a form of free speech by US courts - but this did not sway the courts' decision in favour of the reverse-engineers. An appeal against this decision is currently underway. In an Australian context, any restriction of reverse-engineering appears unlikely to be upheld in court.