Schneier — “Following someone covertly, either on foot or by…”

Source: Data and Goliath: The Hidden Battles to Collect Your Data and Control Your World — Bruce Schneier

Book page: schneier-data-and-goliath-part-1

From: Bruce Schneier — Quotes

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Following someone covertly, either on foot or by car, costs around 175,000 per month—primarily for the salary of the agents doing the following. But if the police can place a tracker in the suspect’s car, or use a fake cell tower device to fool the suspect’s cell phone into giving up its location information, the cost drops to about 70,000 per month, because it only requires one agent. And if the police can hide a GPS receiver in the suspect’s car, suddenly the price drops to about 150 per month—mostly for the surreptitious installation of the device. Getting location information from the suspect’s cell provider is even cheaper: Sprint charges law enforcement only 30 per month. The difference is between fixed and marginal costs. If a police department performs surveillance on foot, following two people costs twice as much as following one person. But with GPS or cell phone surveillance, the cost is primarily for setting up the system. Once it is in place, the additional marginal cost of following one, ten, or a thousand more people is minimal. Or, once someone spends the money designing and building a telephone eavesdropping system that collects and analyzes all the voice calls in Afghanistan, as the NSA did to help defend US soldiers from improvised explosive devices, it’s cheap and easy to deploy that same technology against the telephone networks of other countries.