I was considering purchasing a Nest Protect smoke detector system for my home until I turned my brain on.
The Nest Protect smoke detector has a microphone in it. The purpose for this is to listen at the audio announcements and to determine that the buzzer and speaker are working.
But then I realized Nest Protect was a Google product, and Google has the secret reputation for earning a significant amount of money from spying on citizens and selling this data to governments. (True or not, I don