So your holiday gift was a new smart-home device. It could be Amazon's Echo, often called "Alexa," or Google Home using "Siri," which provide music, news updates and other information features; iRobot Roomba to clean your floors; the Ring doorbell, or a smart TV for voice-command video. Maybe you're thrilled with your gift, or maybe you're a bit wary, given recent reports of cyberhacking of some devices. Internet-oriented devices ...