Here's an idea: A smartphone application that allows users to stream audio and video to a server in the cloud. This could be used to protect citizen against unlawful police (or any other) force.
Currently smartphones have the ability to record data, but these devices can be easily destroyed or confiscated. Applications such as Periscope and Meerkat enable users to broadcast live video streams, but, as far as I know, don't enable them to store the video for later reference.
The idea application would allow for this storage and later reference. A use-case would be: A user is stopped by the police; the user starts the application and the phone's video camera begins observing the interaction; the data from the device is streamed over the Internet to an online server; when the stream is disconnected it is stored securely and indexed to the user's account for later retrieval.
I'd be happy for any feedback on the idea, and if anyone is interested in working to bring it to fruition please let me know. I have the skills to work on creating such an application, but not the manpower to do it in any sort of realistic time frame.