I device you actually talk into all the time -- your phone, if you use Siri or Google voice recognition -- has been doing this for years. Anyone who doesn't realize that speech recognition is sent to servers and doesn't read the privacy policy has only themselves to blame.
On an Apple iPhone or iPad, you have to invoke Siri to have it listen and interpret your voice. It is not listening 24/7 as Samsung's smartTV is apparently listening. Siri only listens when YOU decide you need a specific piece of information and then responds to the question you ask, not to amorphous questions you merely voice while musing in front of the phone. That is not the same thing at all.
There was a post not too long ago on FreeRepublic that indicated that Android phone conversations are being listened to by Google. A freeper commented that he asked his wife what she wanted him to pick up from Wendy's on his way home for lunch. She told him. Not two minutes later a pop-up appeared on his Android phone's screen with a Wendy's Coupon for that very same item. Do you believe in coincidences? I do not. Scary.