A computer-readable storage medium having stored an information processing program therein, an information processing apparatus, an information processing method, and an information processing system, which can efficiently prevent output of inappropriate contents to a recipient. Data including a content is assigned creation information indicating information related to a time when the content is created. Identification information for identifying a content which is inappropriate to be outputted to a user, among contents included in the data received from another information processing apparatus, is previously registered. A content identified on the basis of the previously registered identification information is set so as not to be outputted, whereby only a content which is not set so as not to be outputted can be outputted to the user.