According to the article in BigPond, 41-year-old Qiu Chengwei loaned his "dragon sabre" from the Legend of Mir 3 virtual game world to Zhu Caoyuan. The latter then apparently sold the imaginary weapon to a third party for 7200 yuan (about 900 US dollars). Qui Chengwei was allegedly so angry that he visited Zhu Caoyuan at his house and stabbed him to death.
The incident has created a legal controversy, because Chinese law is unclear on whether a game-world object is protected against theft by the intellectual property laws, or is totally unprotected because it has no physical existence.
Thanks to Baron Folo Watkins of the Middle Kingdom for forwarding the URL to the BigPond article.