Our weekly news round-up: New Facebook patent describes how a TV ad could contain a hidden audio trigger for your smart phone's mic; Raya - the world's most exclusive social network; NASA's NExSS aims to refine how biosignatures are used to assess the chance of life beyond Earth; Saturn's moon Enceladus is releasing plumes of far more complex organic molecules than we thought; Drones using AI to spot violent outbreaks in crowds; China builds the world's first laser assault rifle to vapourise targets within a 1 km range; Amazon Prime is well priced downunder; Much anticipated NVIDIA Shield gaming terminal on sale in Oz.