What does "recording" mean in this context? The way these devices work is they're always "recording" in a loop on a secondary processor looking for the wake word. If we take this request literally the LED would never be off.
That would require, though, that it's not buffering the last N seconds of audio to reprocess once that processor wakes up. Do any/all of the modern smart-speaker devices do that? If so, then you'd have to take into account that when you see the light, you've potentially leaked any secrets you said in the last N seconds as well. Less like a reporter coming in and asking to speak to you; more like an eavesdropper coming in and telling you they heard what you were just saying through the door.
If, even with that expectation, enough people still use "voice assistant" technology for a judge to consider the tech to be "in general public use"[1], the bright line test defined by Kyllo v United States is triggered and the police no longer need a warrant to use the technology (in the abstract - they don['t need to use your hardware) to view "details of a private home that would previously have been unknowable without physical intrusion"[2].
Normalizing the expectation that previously private areas (like the inside of your home) might be recorded and sent to a remote 3rd party will eventually result in everyone losing some of their 4th amendment protection against search and seizure.
[1] http://caselaw.findlaw.com/us-supreme-court/533/27.html
[2] Ibid.
It's like the misguided Prop 65 signs that are in practically every commercial building in California so instead of warning people about dangerous levels of hazardous chemicals, they get a meaningless sign in every building for hazards that are no worse than if they were walking down the street or sitting at home.
As nerds, it makes sense to us to do local wake recognition and only upload a request phrase after that. But in reality, this not the first time[1] we've learned that continuous speech was getting uploaded.
Charitably, it could be a mistake, maybe the previous request never terminated and it just kept streaming. But again, not the first time.
More likely, my opinion, is there's a mountain of cash on the table in the form of private conversation, and AMZ would be foolish to walk away from it. After you talk about "hardwood floors" in your house, you could expect targeted ads, consumer profiling, variable pricing, and third party sales. Why woudln't they do this? Why else are they pushing home devices so hard? They're front and center on the front AMZ page every time you visit, aren't they? Oh and GOOG too, they just haven't been caught yet.
1. https://www.wired.com/2017/02/murder-case-tests-alexas-devot...