Google automatically opting more users into Find My Device
Find My Device network is coming soon
You can use Find My Device today to locate devices when they’re connected to the internet. With the new Find My Device network, you’ll be able to locate your devices even if they’re offline. You can also find any compatible Fast Pair accessories when they’re disconnected from your device. This includes compatible earbuds and headphones, and trackers that you can attach to your wallet, keys, or bike.
To help you find your items when they’re offline, Find My Device will use the network of over a billion devices in the Android community and store your devices’ recent locations.
How it works
Devices in the network use Bluetooth to scan for nearby items. If other devices detect your items, they’ll securely send the locations where the items were detected to Find My Device. Your Android devices will do the same to help others find their offline items when detected nearby.
Your devices’ locations will be encrypted using the PIN, pattern, or password for your Android devices. They can only be seen by you and those you share your devices with in Find My Device. They will not be visible to Google or used for other purposes.
You’ll get a notification on your Android devices when this feature is turned on in 3 days. Until then, you can opt out of the network through Find My Device on the web. Your choice will apply to all Android devices linked to <email@domain.com>. After the feature is on, you can manage device participation anytime through Find My Device settings on the device.
Learn more
https://support.google.com/android/?p=find_offline_devices