The companies say they need this information for the sake of faster response to voice commands as well as ensuing that smart displays have up to date information. It might be difficult to avoid sending at least some continuous information. However, there are concerns the constant supply of data could be used to piece together your habits -- when you leave for work, watch TV and go to bed. That's potentially valuable for marketing and customer research.

Google declined to comment on how it uses continuous data from Assistant, but Amazon said that it doesn't use info for advertising or sell it to third parties. Amazon isn't about to pitch sleep aids because you tell Alexa to turn on the lights at 3AM. The concern is that both Amazon and Google could do this, and that users didn't consent to sharing as much smart home data as they do today.