Amazon’s Echo (and its main competitor, the Google Home) works by passively recording everything you say. None of this information is actually sent to Amazon. Think of it more like taking notes in class — as if you’re listening but not writing anything down until your professor actually says something important. But when the Echo hears “Alexa” (or whatever your activation phrase is), it begins to actively record. That snippet of speech is then sent to Amazon’s cloud servers, where your recorded message is run through a speech-recognition neural network and a response is sent back to you, whether that’s playing a song on Spotify or giving you the weather forecast.
Amazon keeps all of the recordings of you asking Alexa to play WNYC or of you setting a timer for 20 minutes. You can jump into the Alexa companion app and hear all of your requests again if you want to see just how bored you sound when talking to your home voice robot. Sure, it’s slightly creepy — but Amazon also tracks pretty much every move you make while you’re online shopping as well.
Court records show that Amazon twice declined to turn the actual voice-search queries over to the local police, though it also did not comment to the Information about the case in question. For what it’s worth, anecdotally, I’ve heard from a professor who works in voice research that Amazon deletes all voice data after six months — but Amazon has no stated policy about how long it holds onto that data. Still, if any of this has you feeling uneasy about your Amazon Echo, you can always head to amazon.com/myx, find your Echo, and delete out all of your old voice recordings.
In the above case, police confiscated the Echo itself and attempted to extract data from it, but it’s unclear how much they could get — the Echo itself doesn’t have much of a hard drive and almost no information is stored locally on it.