Well, as author and digital rights activist Cory Doctorow explained to me when I interviewed him last year, imagine an Arab Spring-type situation in a country with very cold winters, universal Nest thermostat adoption and a dictator with no ualms about mass surveillance of web and mobile data communications. On the first day of a mass uprising the security services can stick fake mobile signal towers up around the public square of the capital and hoover up the unique identification addresses from the smartphones of every single protester there. (These towers exist, even here.) That night, as the temperature drops to its bitter coldest, every single protester finds their heating system remotely disabled. Hypothermia takes care of the dictator’s problem.

This is not science fiction. It’s entirely possible with existing technology, and only made unrealistic because that technology hasn’t reached universal rates of adoption. This is the upcoming Internet of Things, if we’re not careful.