Many of today's mobile services build mobile communities of users who share their valuable experiences and data. Examples include traffic incidents (Waze), restaurant reviews (Yelp, FourSquare), anonymous social networks (Whisper, Yik Yak), and even dating (Tinder, Bumble). Unfortunately, new threats can compromise and manipulate these communities, using lightweight software to mimic mobile devices. The resesarchers have shown how attackers can eavesdrop on mobile network traffic, learn their patterns, and write software to emulate mobile devices running the application.