How a phone in your pocket can be located, tracked and even overheard
A mobile phone reveals its position even when idle. By comparing how long its signal takes to reach several nearby towers, a technique called multilateration pins down the handset and whoever carries it. In one year, federal agencies asked a single American carrier, Sprint, for customer location data 8 million times.
Fake towers go further. The StingRay, first built by the military for counterterrorism, broadcasts a signal strong enough that nearby handsets hand over their IMSI identity number as if talking to a genuine mast. The owner gets no sign of it, while the operator can pull out location, calls and texts. British and American agencies can also switch on a phone's microphone remotely through its diagnostic or maintenance features, listening to conversations near whoever holds it.
Computers leak too. Van Eck phreaking reads the electromagnetic emissions of devices to reconstruct data from hundreds of metres away, and FBI tools such as Magic Lantern and CIPAV can be planted on a machine physically or remotely. Because internet traffic is far too vast for people to read, automated systems filter it for trigger words, suspicious sites and contacts, and only flagged items reach human analysts. Speech-to-text software does the same for intercepted calls, deciding which ones deserve a live listener.
In the United States, the Communications Assistance for Law Enforcement Act obliges carriers to make phone and broadband traffic available for real-time monitoring. AT&T and Verizon were paid $1.8 million a year by the FBI to keep call records searchable, and between 2003 and 2005 the bureau issued more than 140,000 National Security Letters demanding customers' calling and internet histories. After Edward Snowden's leaks, Apple designed the iPhone 6 to encrypt data with a key it could not itself read, drawing complaints from FBI director James Comey.
Cameras are the most visible layer. About 350 million watched the world in 2016, some 65% of them in Asia, and China alone was reported in 2018 to run over 170 million. New York's Domain Awareness System links 18,000 CCTV cameras monitored by police and software.
Source: Surveillance
