What data do smart home devices actually collect?
More than the function requires, in many cases — and the useful distinction is between data needed to operate the device, data used to improve the service, and data used commercially.
What is genuinely collected, by category:
Smart speakers store the audio and transcripts of recordings made after the wake word, plus your requests and history. They are not continuously recording and uploading, but false wake activations are common, and those recordings are retained and have historically been reviewed by human contractors for quality purposes — which several manufacturers did not adequately disclose.
Cameras and doorbells collect footage, motion events, timestamps and sometimes faces. Cloud storage means footage sits on a company's servers, and access by employees and disclosure to police have both been the subject of controversy.
Thermostats collect temperature, occupancy patterns and schedules — which reveal when a home is empty.
Smart plugs and lights collect usage timing, from which activity patterns are inferable.
Televisions collect viewing data through automatic content recognition, which samples what is on screen to identify it — including from external inputs. This has been subject to enforcement action for inadequate disclosure, and is frequently enabled by default.
Vacuum robots collect floor plans of your home, which are commercially valuable.
Voice assistants on any device collect interaction history.
What the aggregate reveals. Individually innocuous signals combine into a detailed picture of occupancy, routine, sleep, household composition and absence — which matters for advertising, for insurance and for physical security.
What you can actually do:
Check privacy settings on setup, since defaults favour collection. Turn off content recognition on televisions, which is usually buried.
Review and delete stored recordings, and turn off human review where offered.
Prefer local processing and local storage where the product supports it.
Segment devices onto a separate network, limiting what a compromised device reaches.
Check the update policy before buying. An unsupported device becomes a permanent vulnerability inside your home.
Exercise access and deletion rights, which apply to this data.