1. A method for processing spam contents, comprising the steps of: maintaining a plurality of key information databases; receiving user-created content and at least one of a service identifier (ID) and a content category ID of said user-created content from one or more users of a user-created content hosting site; selecting at least one of the plurality of key information databases based on at least one of the received service ID and the received content category ID; extracting second key information from the received user-created content; searching the selected key information database to retrieve first key information related to the second key information; classifying the user-created content as spam content based on the extracted second key information and/or the retrieved first key information related to the second key information; and conditionally storing the user-created content in a network accessible data store available to users of the user-created content hosting site based on classifying the user-created content as spam or non-spam content wherein, the second key information is different from the service ID, and the second key information is different from the content category ID.