Yet not paying that price has its own cost: an inability to participate in some of technology's greater achievements. Because smart gadgets thrive on data data about you and your habits, data about what large numbers of people do or say or appear to want in particular situations it's difficult not to share pretty much everything with them. Does the "don't talk to strangers" rule apply if the stranger is the Hello Barbie talking doll or Dino, the dinosaur powered by IBM's Watson artificial-intelligence system? Cars will work with GPS technology and sensors in parking meters, roads and home appliances to help route you around traffic and turn on your living-room lights as you approach the driveway. Wearable health devices will track your heart rate, fitness levels and more and share achievements with friends and family. [...] maybe it's less so when your phone knows enough about you to remind you it's time to leave for an important interview (if the alternative would be losing a shot at that job) or your smart home can really tell you if you turned off the oven before leaving for an international trip. [...] convenience usually wins. Though it does store conversations between kids and their dolls to improve speech-recognition technology, its maker says there's little personal information tied to those conversations no first or last names, no ages, no gender. ToyTalk employees who review such conversations to improve the technology are trained to immediately delete anything sensitive, but they aren't charged with actively monitoring stored discussions. Many services ask for birth dates, phone numbers and even income levels just because they can and few people resist.