Nowadays, automobiles have a role as a sensor aggregation which is used to grasp the circumstance and its locational information. The value from sensors on each vehicle is called probe data. Organically-consolidated probe data which make social seminal information is deserving of societal expectation. These probe vehicle systems also known as floating car Data System (FCD) are developed under active promotion of cooperation among industry, academia, and government. In addition, for providing global social services over the Internet, lots of companies and general persons who use such services have drew attention to privacy, especially the management of personal data. In this paper, After providing a brief overview of general probe vehicle system, we sew up practical difficulties and threat analysis. Base on its analysis, we consider the requirements for envision a design and deployment of secure probe vehicle system, and inform the related activities at ISO.