I've been seeing a lot of recent excitement on the Diablo 3 forums about user operated gambling, the most popular of these being the Arena / PVP Gambling.
It's no surprise that a lot of players are highly supportive of gambling within the game and all of this was bound to happen. They're already talking ideas on how to do it, rules, and making initial preparations well in advance of the game's release.
My favorite part was when a user said that placing a wage on an arena fight was not illegal or gambling because their actions are skills-based and there's no luck involved. I love hearing all of these justifications. :)
What's interesting about these forum posts, though, is that they're not being told NOT to do this. These forums are moderated, and when players start talking about gambling, cheating, exploitation, or discrimination in WOW forums, for example, they are reprimanded and censored.
All of this reminds me of classic internet libel cases. Companies are much more "protected" if their forums are left unmoderated because they have no control over what users post. The logic goes something like this; if you have a forum that is unmoderated, it's like a library where users can write libelous material in their books. They don't know about it, and hence can't be held responsible for it. However, if you have complete control over all subject matter and approve what is written, then you are responsible for all content and "officially support" what is written.
Now, that specifically deals with libel of course, but it can also apply directly to personal opinions within any moderated forum. If a forum is moderated and content is reviewed, then anything that is written is "supported" by the forum owner. When you talk bad about a company (their game, rules, people, etc), the content is deleted or edited. Good, supportive, and praising comments are left alone. Of course, some posts are hard to spot, and those get by, but when you have very popular (and multiple) posts with thousands of players saying the same thing, then whatever they write (or the idea they are promoting) is essentially "supported" by the company. :)