Drill · loss
Lost or stolen phone
Procedure taughtWalk the real "Loss or theft" flow from the client sheet: at-rest encryption, auto-reboot, then self-hosted Find My Device (locate / wipe "best-effort").
Your phone is gone. The first move is not panic: it is to understand which protections already act on their own, and what Find My Device can — and cannot — do.
Start here
The phone has been missing for ten minutes. What is ALREADY protecting you, without doing anything?
At-rest encryption + the lockGood move
ConsequenceCorrect. A locked phone is unreadable, even stolen: that is the first protection, and it is already active. Auto-reboot will then return it to the encrypted (BFU) state after a period of inactivity.
SourcesGrapheneOS — Auto reboot
You open Find My Device (self-hosted on fmd.onsecret.net). Is the device reachable?
FMD receives its commands via push notification (UnifiedPush / ntfy). So the phone must be powered on AND connected to the network.
Yes — powered on and onlineGood move
ConsequenceYou can attempt a coarse locate, a lock, or a remote wipe. Location is "best-effort": it depends on the GPS/network of the moment, not on continuous tracking.
SourcesFind My Device (FMD) — projet
Which action do you trigger?
Remote wipeGood move
ConsequenceWipes the device if it receives the command. "Best-effort": with no network, nothing goes out. Pair this with the fact that the content was already encrypted at rest anyway.
Locate only, then decideNuance
ConsequenceReasonable. Reminder: an FMD locate is one-off and coarse — useful for "left at a friend’s" more than for chasing a mobile thief. Never put yourself in danger to recover an object.
No — powered off or offlineNuance
ConsequenceAn honest and important limit: FMD is INOPERATIVE if the phone is off or offline. No command arrives. Your protection then remains at-rest encryption — hence the value of a strong passphrase.
SourcesFind My Device (FMD) — projet
Which action do you trigger?
Remote wipeGood move
ConsequenceWipes the device if it receives the command. "Best-effort": with no network, nothing goes out. Pair this with the fact that the content was already encrypted at rest anyway.
Locate only, then decideNuance
ConsequenceReasonable. Reminder: an FMD locate is one-off and coarse — useful for "left at a friend’s" more than for chasing a mobile thief. Never put yourself in danger to recover an object.
Nothing until I act remotelyNuance
ConsequenceFalse — and that is good news: your data is encrypted at rest regardless of any remote action. FMD is a "best-effort" complement, not the main barrier.
You open Find My Device (self-hosted on fmd.onsecret.net). Is the device reachable?
FMD receives its commands via push notification (UnifiedPush / ntfy). So the phone must be powered on AND connected to the network.
Yes — powered on and onlineGood move
ConsequenceYou can attempt a coarse locate, a lock, or a remote wipe. Location is "best-effort": it depends on the GPS/network of the moment, not on continuous tracking.
SourcesFind My Device (FMD) — projet
Which action do you trigger?
Remote wipeGood move
ConsequenceWipes the device if it receives the command. "Best-effort": with no network, nothing goes out. Pair this with the fact that the content was already encrypted at rest anyway.
Locate only, then decideNuance
ConsequenceReasonable. Reminder: an FMD locate is one-off and coarse — useful for "left at a friend’s" more than for chasing a mobile thief. Never put yourself in danger to recover an object.
No — powered off or offlineNuance
ConsequenceAn honest and important limit: FMD is INOPERATIVE if the phone is off or offline. No command arrives. Your protection then remains at-rest encryption — hence the value of a strong passphrase.
SourcesFind My Device (FMD) — projet
Which action do you trigger?
Remote wipeGood move
ConsequenceWipes the device if it receives the command. "Best-effort": with no network, nothing goes out. Pair this with the fact that the content was already encrypted at rest anyway.
Locate only, then decideNuance
ConsequenceReasonable. Reminder: an FMD locate is one-off and coarse — useful for "left at a friend’s" more than for chasing a mobile thief. Never put yourself in danger to recover an object.
What this drill proves
The real first protection when a phone is lost is at-rest encryption, active without doing anything. Self-hosted Find My Device adds "best-effort" locate and wipe — useful but fallible. onsecret hosts FMD on its own infra (no Google) and explains its limits rather than hiding them.
- FMD is "best-effort": inoperative if the phone is off or offline.
- Location is one-off and coarse, not continuous GPS-precise tracking.
- FMD must be registered and authorised as a device admin BEFORE the loss — not after.
- Never take a physical risk to recover a device: the data was already encrypted.
Sources: Find My Device (FMD) — projet · GrapheneOS — Auto reboot