Information, goes the old saw, wants to be free. Apparently, it wants to be everywhere, too. That at least is the implication of the "Internet of things" (IoT), a system that connects an ever-expanding array of sensors to the Internet and to each other.

Those linkages facilitate not only communication among those devices but the collection and analysis of vast amounts of data. The Internet of things is on the cusp of becoming a reality, creating an extraordinary new range of opportunities and dangers.

Historians trace the IoT back to 1982, when computer scientists at Carnegie Mellon University, one of the leading centers of computer study in the United States, grew frustrated by frequent trips to the building's Coke machine only to discover that it was empty. They installed a sensor in the dispenser and made it accessible through the computer network so that anyone, anywhere, could remotely check the status of the machine (as well as the availability of soft drinks).