There are some claims coming out that if you talk in front of some of these devices you will get targeted ads sent to you. Dont know if Alexa is one of them.
So for example, I am going to go to Hawaii...and from there.
I have seen a similar thing when looking at something online that I am thinking of buying ..and then it shows up in targets ads. See that quite a bit. So I can see it being taken a step further with voice.