This paper represents preliminary recommendations regarding the development of a privacy preserving system design framework related to the EU project, ePOOLICE, which aims at developing an environmental scanning system for fighting organized crime by providing law enforcement agencies opportunities for strategic proactive planning in response to emerging organized crime threats. The environmental scanning is carried out on a variety of sources, focusing on early warning and the disclosure of crime trends, not on individuals. Consequently, personal data are not relevant in the information context of ePOOLICE, and therefore the system will not make use of any kind of sensitive information. Particular attention are paid to the environmental scanning of data streams from social networking sites; based on the assumption that ethical and privacy issues with regard to social media scanning represent a significant challenging scenario to meet in developing a privacy preserving framework for ePOOLICE.