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| observations of signalling traffic (Signalling messages are commands that are sent by a telecoms operators across the global network, unbeknownst to a mobile phone user. They allow operators to locate mobile phones, connect mobile phone users to one another, and assess roaming charges. But some signalling messages can be used for illegitimate purposes, such as tracking, monitoring, or intercepting communications. // Guardian, 2020 Alex_Odeychuk) | |||