A method for selectively blocking a remote purchase request based on previous remote purchase requests. The method starts with receiving and storing, in a memory subsystem, information from purchase request information sets including, for each purchase request information set, an origin, a card number...http://www.google.com.hk/patents/US6714919?utm_source=gb-gplus-share專利 US6714919 - Device for selectively blocking remote purchase requests
