ESWN has translated portions of a document from the Guangdong Province Department of Telecommunications outlining self-censorship guidelines for BBS operators. The original document is here. From ESWN’s commentary:
This type of delegation of the regular daily censorship duties should not be surprising.  It also occurs in the United States and elsewhere.  For example, if someone starts distributing kiddie porn through AOL, MSN or Yahoo!, then the operator has the responsibility of suspending and terminating the user and/or reporting the facts to law enforcement.  The difference between China and the United States lies in the list of banned activities.