Global Navigation Satellite System (GNSS) technology is growing fast in our society and new applications are being introduced at an unprecedented pace. The GNSS products provide worldwide and real-time services using precise timing information, positioning and synchronization technologies. Within years, GNSS applications are becoming more accurate and their precision opens doors to a wide range of applications. Nevertheless, these applications are susceptible to disruption in the operation of GNSS receivers when malfunctions, failures or interference occur. This paper’s objective is to make an overall analysis of GNSS failure impact on society and therefore make a review of GNSS spectrum protection strategies. In the first three sections of this analysis, we survey GNSS applications, their importance and their criticality. While questioning the criticality of GNSS applications, we evaluate their impact on main critical infrastructures and particularly the risks of critical dependencies in case of failure or interference. In the last two sections, we investigate GNSS spectrum interference in relation to its effects on crucial infrastructures. We review the principal Radio Frequency Interference (RFI) sources leading to GNSS and satellite communications (SATCOM) spectrum issues. Alongside, we study various ways to mitigate RFI. This process is essential to further develop and standardize mitigation techniques and to ensure GNSS spectrum immunity against RFI.