To be fair, the researcher and the article are making a lot of assumptions a default configuration of a basic device don't have right out of the box. If you have a smart home, or even smart lighting, and you enable your app to track you by your phone, thereby knowing when your proximity to your home is so it can adjust the heat, turn on lights, unlock the door, etc. All of these things require the end user to actively configure (or have configured for them) parameters which yes, could track a person. However, just because you have Brand A device in your home and another person has the same device, you going in proximity to their device doesn't automatically know you are there. Currently you are more likely to be outed by your phone more than a smart device. But...as we go down this road, and we begin to develop more and more creative uses for these devices, and just like with friends on Facebook, you add friends to your smart device so that when Bob comes over your home knows to play Led Zeppelin because that's what Bob likes, then you could see this being more realistic. The article seems to be a 'be very afraid' of technology kind of article without a lot of real substance to back it up. The potential is really there, but even the article says in apartment buildings based on behavior you could infer something happened, meaning I come home, turn on the lights in apartment 1B, then I leave and turn off the lights and then the lights go on in apartment 3C, it could mean I went up to 3C. Could also mean 3C came home. It's always smart to protect your privacy, and urge your elected officials to start putting something in place here in the US that they have done in the UK (GDPR, which goes to great lengths to make companies make your data your own) so we can have similar control over our data. Note the Amazon devices all come with a button you can press so that it stops listening to you. There is also the unplug it from power option!