Well they do log surrounding network hardware which are broadcasting, so visible Bluetooth, devices on the same wifi, the APs themselves, etc. This allows a rou

Well they do log surrounding network hardware which are broadcasting, so visible Bluetooth, devices on the same wifi, the APs themselves, etc. This allows a rough estimate of the locations of visible devices which are not made by Apple. The only way to opt out of that is to not be visible on public networks and to not bring an iPhone onto your house network.