The past few years have witnessed the explosive growth of Cyber-physical System (CPS) and Internet of Things (IoT). These phrases emerged from different communities, but they refer to a related set of trends in integrating information and communication technologies (ICT) with engineered systems and physical devices to enhance performance and functionality. From a unified perspective, the emerging convergence of CPS and IoT concepts is referred to as CPS/IoT. While CPS/IoT bring unprecedented efficiency and productivity, the embedded information system, especially if wireless communications are used, exhibits vast vulnerabilities for adversaries to explore. This talk covers three aspects of CPS/IoT, its security, privacy, and network intelligence, and the third one will be expanded in specific. This is an interdisciplinary study, wherein fundamental connections between local responses of shifting in graph signal processing (GSP) field, and the system observability in control theory are established. It serves as a starting point to reinterpret GSP from the viewpoint of control theory, and it is promising to develop this field further by establishing fundamental theories and practical applications.