The proliferation of consumer drones are presenting real security and privacy concerns for event managers of conventions, festivals and concerts and all kinds of sporting events. http://www.athleticbusiness.com/stadium-arena-security/drones-emerging-as-security-threat-at-domestic-sporting-events.html#.WCodyGEmQWk.email
DeTect, Inc. has recently released on Google Play the the DroneWatcherAPP that makes an Android smartphone or tablet into a personal drone detector. The app monitors for drones up to 1/2 mile providing both audible and visual alerts when a drone is detected. The app can be downloaded for free on Google Play.