Methods and systems for deterring spam on a communication medium are disclosed. Call traffic on the communication medium includes IP telephone calls, IM™ messages and other IP calls. The method includes detecting a call with a user device for accessing the communication medium, such as an IP telephone,...http://www.google.com.tw/patents/US20070041372?utm_source=gb-gplus-share專利 US20070041372 - Method and system for deterring SPam over Internet Protocol telephony and SPam Instant Messaging
