What are citizens of a free country willing to tolerate in the name of public safety? Jon Fasman journeys from the US to London - one of the most heavily surveilled cities on earth - to China and beyond, to expose the legal, political, and moral issues surrounding how the state uses surveillance technology. Automatic licence-plate readers allow police to amass a granular record of where people go, when, and for how long. Drones give the state eyes - and possibly weapons - in the skies.

Algorithms purport to predict where and when crime will occur, and how big a risk a suspect has of reoffending. Specially designed tools can crack a device's encryption keys, rending all privacy protections useless. And facial recognition technology poses perhaps a more dire and lasting threat than any other form of surveillance.

Jon Fasman examines how these technologies help police do their jobs, and what their use means for our privacy rights and civil liberties, exploring vital questions, such as: Should we expect to be tracked and filmed whenever we leave our homes? Should the state have access to all of the data we generate? Should private companies? What might happen if all of these technologies are combined and put in the hands of a government with scant regard for its citizens' civil liberties?Through on-the-ground reporting and vivid storytelling, Fasman explores one of the most urgent issues of our time.