Re: Not their call
I've considered building something along the lines of an echo for my house. Mine would have a Raspberry Pi at it's heart - like every other IoT device in my home because I don't trust internet connected devices built with non-existent security considerations and programmed by God-only-knows-who - and use a fully local speech recognition engine. I see no reason to stream commands to a server controlled by someone else when even the cheapest processors have plenty of power to handle the level of speech recognition needed for what these things do.
Basically I'm sort of assuming that the Echo - along with Siri, Cortana, and everything that responds to the phrase "OK Google" - is eavesdropping and collecting data to sell to advertisers.