A filtering apparatus includes an illegal request DB (database) which stores patterns of illegal accesses to a Web server, an estimation section which estimates the legality of an access request from a client device based on the illegal access patterns stored in the illegal request DB and on a predetermined...http://www.google.de/patents/US20020133606?utm_source=gb-gplus-sharePatent US20020133606 - Filtering apparatus, filtering method and computer product
