Terrorism has been an unending trouble in human history. It is obvious that with twenty first century, new age of terrorism has started. Terrorism is transnational, institutionalized, technologically advanced, and global. Today s terrorist organizations are using Internet for different purposes. The Internet has become the new and main source of communication in terms of disseminating propaganda for terrorist activities. In this context, PKK terrorist organization, as part of terrorist community, is exploiting the Internet for its purposes and broadcasting propaganda through its websites. This study is focused on the exploitation of Internet by terrorist organizations for their activities and to examine PKK terrorist organization, as a case study.