73 Surveillance vehicle, Warsaw, Poland, 9 July 2016, ©ODIHR Signal jammers are used to generate disruptive signals across the radio frequencies used by mobile phones, wireless Internet and other communications devices and networks, in order to block communication with antenna towers, thereby preventing communications technologies from being used within a certain area. Jammers vary greatly in appearance and size, with some having multiple antennae. Models promoted for law enforcement use include devices integrated into backpacks, clothing or laptops, devices intended to be installed in a fixed location, devices designed to be installed and used in vehicles and standalone, portable devices. Signal jammers have been used to make electronic communication difficult or impossible at an assembly including, including the transmitting of live video feeds or posting to social media. Interception technologies (IMSI catchers, phone and fibre taps, malware, etc.) are designed to covertly access and/or record and store information communicated over the Internet or mobile, fixed or next generation networks. Certain technologies can also change (or insert) messages sent or received by mobile devices. Existing systems for intercepting and monitoring phones can be integrated