Essential developments on computer systems and space technologies have given rise to GNSS (Global Navigation Satellite Systems) enter into our daily lives. T he positional and navigational advantages provided by GNSS have caused it to be perceived as a basic requirement from the application point of view particularly in developed countries. On the other hand, the applications of GNSS have generally proceeded without taking into consideration legal issues up to now. And this lack of legal issues may cause serious problems for GNSS applications in near future. Because, US GPS (Global Positioning System) has been used as the only global positioning system as open service to all users and thus all the rules were determined and dictated by USA until now. But later on other countries such as Russia, EU, China etc. began to establish their own satellite systems in order to get rid of US GPS dependency only. As a result, currently, there are mainly three global (i.e. GPS, GLONASS and GALILEO) and three regional (QZSS, Beidou/Compass, IRNSS/GAGAN) GNSS service providers in use and thus it seems that legal issues are going to be more important when all these satellite systems become fully operational in space in 2020.