According to ChuTianJinBao ¨C a local newspaper in China, a man was beaten to death because he recorded city guards' rude activities on his cellular phone.
On January 7, city guards used violence in Tianmen City. A man recorded the abuse of power. City guards asked him to delete the contents, the request was refuse, then the city guards beat him. The man was sent to hospital and died. http://www.peacehall.com/news/gb/china/2008/01/200801081613.shtml

It becomes more and more often that city guards beat and kill people.
Boxun reported three major incidents in 2007, none of city guards received penalty; in contrary, all reporters sent the information to Boxun were harassed: SUN Lin (Nanjing City) was arrested on May 30 2007, still in jail. Another one was interrogated. Most recently, city guards killed one man in Changsha, the police threaten witnesses and did not arrest anyone.

Update on Jan. 13 (NY Time): The man happened to be a CEO of a company, after he was died, family members and local people gathered together and protested. They threw away the sign of the city guard's office building (picture below)

Boxun just leanred that there was another one died in hospital the second day of the beating incident. It is still kept as secret by local government.

Internet user in China composed the pictures of city guards beating people:

http://news.boxun.com/forum/200801/pic/4212.shtml