Is Your Thermostat Spying On You?

When left home alone, cats spend 22 percent of their time looking out of windows, 8 percent climbing chairs and 6 percent sleeping. A researcher collecting data for a pet manufacturer figured that out by fitting 50 cats with camera collars that took pictures every 15 minutes. That was four years ago. Now the animal testing phase is over: The Internet of Things is about to turn people into the equivalent of those experimental cats, with more sophisticated tracking devices.

Nest, the intelligent device producer Google is acquiring for $3.2 billion, makes thermostats and smoke detectors that interact with owners' smartphones. So is there any reason to worry that the devices will track your movements while you're at home, record your behavioral patterns and share the information with Google, which will then use it for commercial purposes? After all, Google is mainly in the advertising business.