A fascinating look at a serious question for observant Jews on whether one can use Amazon's Echo (and presumably other voice-activated hands-free devices) on the sabbath. Observant Jews interpret the Third Commandment, to keep holy the sabbath, to mean that no labor that is not strictly necessary can be done. For example, in Israel on the sabbath, all elevators stop at every floor so one doesn't have to push the button for their floor.
So what about asking a device to do something for you? Evidently not. I don't begin understand the technical details of Jewish law--and since there is no single magisterium in Judaism, it apparently comes down to the interpretation of particular rabbinical leaders--but the fact that your speaking causes the computer to do some type of processing and because Echo is always on and thus always processing in response to speech, then it is doing forbidden work. I apologize to my Jewish readers if I'm mangling that. I welcome corrections in the comments.
A related question asked if Echo (or to be more accurate, the Alexa assistant) is a new kind of "Shabbos goy", a non-Jew allowed to do some work for a Jew on the sabbath. The answer seems to be No.
What kind of questions might tech like this raise for Catholics in the future? For instance, if Siri/Cortana/Alexa/Google Now is always listening, should priests leave the smartwatches, smartphones, and tablets outside of the confessional?
P.S. I know "kosher" isn't the right word. I'm using it in the more expansive sense it's acquired in popular culture to make a bit of a pun. Sorry.
Actually, the elevators are more complicated than you state. Pressing a button would be work, but also adding your weight to an elevator causes more work. Elevators (generally) save energy by pulling only with the force needed to move their load. So, not only does the elevator stop on each floor but its motor is fixed to always pull with constant force.
The prohibition on work on the Shabbos, was extended to electronics by equating electricity to fire. You are not allowed to start a fire, and flipping a switch causes a spark, which is fire, so electronics are therefore not allowed.
As an electrical engineer, I think an always on, solid state (no moving parts) device should be technically allowed, but it does violate the spirit of the Shabbos.