Many of us believe the rules of regular life apply to our online interactions; a good measure of whether or not a comment is appropriate is if you'd say it face-to-face. This standard does not hold across all cultures. David Herold in the Journal of Virtual Worlds Research uses Bakhtin's carnival as a metaphor for how a Chinese person feels about their persona online.
The "life of the carnival square" is the antithesis to the boring and ordinary lives people live outside the carnival, thus offering them an escape, albeit temporarily, from their drudgery (Bakhtin, 1984b: 8f). The carnival 'space' and 'time' are set apart from 'normal' life, and none who enter them escape its influence, as "by its very idea carnival belongs to the whole people, it is universal, everyone must participate in its familiar contact" (Bakhtin, 1984a: 128). The carnival offers entertainment, freedom from rules, universal good will, etc. in contrast to the oppressive reality of people's lives. Chinese cyberspace appears to play a similar role in the lives of Chinese people, who engage in relatively anonymous, wild, and fun activities whenever they are online, which are thought to be disconnected from their offline lives and identities but nevertheless have an impact on Chinese society offline.
The author of the article introduced Chinese students to the world of Second Life, where they felt the freedom to be rude. In interacting with other avatars, they felt no need to observe social conventions. One student wrote that he felt people are not accoutable for their actions online.
In the game, people are not liable of what they have done. It is because that is not a real world. So that people may do or talk something they fear in the real world. In the game, it is a good opportunity to let them show their real face of themselves. For example, I always tell lies in the game, because it is just a fake character in the game, not a true me. I do not need to take any responsibilities of what I did.
So if you meet some rude Chinese teenagers in World of Warcraft, chalk it up to cultural differences.