Mobile World

Cell phones have numerous privacy issues associated with them, and are regularly used by governments to perform surveillance.
Law enforcement and intelligence services in the U.K. and the United States possess technology to remotely activate the microphones in cell phones in order to listen to conversations that take place nearby the person who holds the phone.
Mobile phones are also commonly used to collect location data. The geographical location of a mobile phone can be determined easily (whether it is being used or not), using a technique known multilateration to calculate the differences in time for a signal to travel from the cell phone to each of several cell towers near the owner of the phone.