RF-based WPTNs are deployed to transfer power to embedded devices over the air via radio frequency waves. Up until now, a considerable amount of effort has been devoted by researchers to design WPTNs that maximize several objectives such as harvested power, energy outage, and charging delay. However, inherent security and safety issues are generally overlooked, and these need to be solved if WPTNs are to become widespread. This article focuses on the safety and security problems related to WPTNs and highlights their cruciality in terms of efficient and dependable operation of RF-based WPTNs. We provide an overview of new research opportunities in this emerging domain.