The owner of a virtual world has the right to make the rules. Normally a user signing on will be offered a terms of service agreement and must indicate that they read and will observe the terms of service. It’s like a shrink-wrap law wherein use of the product is prima fascia evidence of an agreement to comply with the terms. Guidelines are often developed to make the behaviors specified in the terms of service clear to the user population. Chat rooms have a System Operator (SysOp) these individuals are empowered by the owner to enforce the terms of service and employ a host of sanctions consisting of , muting, denial of specific functions and ejection. Virtual worlds have in-world police or moderators who perform the same function.
A user who violates the terms of service is breaking civil law because they break the terms of service and therefore create a violation of the contract or use of the service. This argument I believe world stand in favor of the owner if sued for denial of service.
There arise two realms of law in this arrangement. The first is real world law breaking and the second is guideline/terms of service violation.
Real crimes that traffic in virtual worlds include money laundering, child pornography, and credit fraud. It could include stalking if so specified in a restraining order. All of these offensives are outside of the control of the owner and must involve real world police.
The second is the pseudo-law based on the owner’s terms. Generally these deal with freedom of speech/expression issues. Oddly it could be argued that a user who signs into a virtual world and by so doing accepts the terms and conditions gives up first amendment rights. SO the entire body of in-world law can be pretty much what the owners says...(My house my rules)
Activeworlds has a police force to enforce guidelines and has successfully maintained a non abusive environment in the commercial universe hosting Alphaworld one of the earliest still operating virtual communities (www.activeworlds
I gave a presentation recently at the 3D Training, Learning and Collaboration (3D TLC) in April. There is a briefing related to this subject.