Energy harvesting at radio frequencies (RF) is increasingly attracting interests because of the simplicity of its concept: collecting the RF energy through an antenna and a rectification circuit. This enables power-over-distance transmission, recharging of devices and communications and many other applications. However, the transferred power levels are inadequate due to uncertainties on the scenario and a non efficient confinement of the power transfer. In this work, the feasibility of a radically new approach based on RF field intensity focusing in unknown scenarios is discussed. The proposed approach is, in principle, able to maximize the energy transfer as it aims at confining the RF power on the considered RFID device. Moreover, being the approach based on a real-time procedure, it is able to deal with moving RFID tag embedded into an unknown scenario. Finally, the achieved spatial confinement will deliver private Peer to Peer communication.