> The NSA will likely record every sound from your house, if you own this.
It would be very easy to detect something fishy was going on. Even if the device was locked down and the connection was encrypted, they couldn't hide it if the device was uploading large volumes of data with no explanation.
You don't need to upload large volumes of data for voice recognition (see Siri), and if you're only looking for specific keywords/sentences you can trickle the data over time.
Yes, but that's not what the person I was responding to said. They said the NSA would record every sound in the house, which would require a detectable amount of bandwidth even at low bitrates.
The hotword detection (OK Google/Hey Siri/Alexa) currently happens on the device - it would be terribly inefficient to do that in the cloud. If a security researcher notices their Google Home is transmitting significant amounts of data without them using the "OK Google" prompt, that would raise eyebrows.
Siri, Google Now, and the Amazon Echo do audio processing in the cloud, but only after they've been triggered by "OK Google" "Hey Siri", or "Alexa". (Or by hitting a button.) It'd be pretty odd, and terribly inefficient, if the Google Home did hotword detection in the cloud.
It would be very easy to detect something fishy was going on. Even if the device was locked down and the connection was encrypted, they couldn't hide it if the device was uploading large volumes of data with no explanation.