Location-based services (LBS) become more feature-rich and versatile due to the explosion of mobile devices and the advances of positioning technologies. However, revealing personal private locations to potentially un-trusted LBS server and others may raise serious privacy concerns if these locations are not protected adequately. In this paper, we present a survey of existing methods dealing with outdoor and indoor localization techniques and location privacy protection techniques. We propose a

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... taxonomy that summarizes the state-of-the-art. This survey is intended to help researchers in quickly understanding existing works and challenges, and possible improvements to bring.