it could store the recordings and bundle them with an innocent request, encrypted even. unless you have physically looked inside the device and checked that it is incapable of doing this, you are simply trusting a company's word.

Plenty of people have done just that; And discovered that no, Echo devices do not do that. Also audio recordings are big, so the folks who have done proper network analysis would probably have noticed such a thing.

Echo devices have two computers in them: One that only listens for the wake word and activates the second computer. A second computer that does the actual relay and processing for the voice commands.

Claiming they're always recording is just unnecessary fearmongering