NIT
If it isn't always listening, then how does it process the command word??
What can these devices still do when there is no connection? (besides complain about NC).
This assumes (by me) that they don't store and forward at a later time some 'trapped' keyword data.
I can't believe there are not ways to fake 'not listening' (or looking thru your camera on equipped devices). Then there is the cases of rogue employees including (unsanctioned) backdoors
for entertainment purposes 
Not all exploits are sanctioned by the company. You should still take care.
(my WEBCAM has a lens cap, that was included in the package. The Mic is still there)