I've read white-paper about data that iOS and Android devices send when NOT IN USE, so that you don't have to. Situation is really bad, even when user opted out of telemetry devices continue to send data to A and G respectively. Aside from everything else, one area that I'd like to highlight is MAC addresses of nearby devices, along with gateway that iOS devices send, if exposed 3-rd parties may learn a lot about devices in your household. https://www.scss.tcd.ie/doug.leith/apple_google.pdf