Communicating with and/or monitoring of a targeted used in computer-network environment (e.g., an instant messaging system) involves detecting that the targeted user has signed on to the network, and upon detecting the signon, automatically communicating with the targeted user, for example, by sending...http://www.google.com.tw/patents/US6691162?utm_source=gb-gplus-share專利 US6691162 - Monitoring users of a computer network
