The combined advances of open mobile platforms and online social networking applications (SNAs) are driving pervasive computing to the real-world users, as the mobile SNAs are expected to revolutionize wireless application industry. While sharing location through mobile SNAs is useful for information access and user interactions, privacy issues must be addressed at the design levels of mobile SNAs. In this paper, we survey mobile SNAs available today and we analyze their privacy designs using feedback and control framework on information capture, construction, accessibility, and purposes. Our analysis results suggest that today's mobile SNAs need better privacy protection on construction and accessibility, to handle increasingly popular mashups between different SNA sites. We also identify two unexpected privacy breaches and suggest three potential location misuse scenarios using mobile SNAs.