Japanese company KDDI has developed technology for cell phones that uses something called accelerometers to track precise movements, then beams all that info back to a central location. And we're not throwing the word "precise" around willy-nilly here. These guys can tell if whoever wearing the phone is sweeping versus scrubbing, walking versus running, doing number two in the bathroom versus doing number two in the secretary's filing cabinet. It's that sophisticated.
Considering how much we use technology in our lives, it's scary just how easily our gadgets can be turned to spy on their owners. Consider the amount of information that passes through your computer or cell phone - the ability to log every keystroke or read every single text message gives someone the knowledge of your ongoings. Of course, these are only the most basic ways of spying, on you, through your technology.