Find My on a Mac: what it can and cannot do
· 5 min read
Find My is usually described as locating a lost device. On a Mac its more valuable function is Activation Lock, which makes a stolen machine unusable by anyone else.
Worth knowing what it does before you need it.
Turning it on and checking
System Settings, your name, iCloud, then Find My Mac.
There are two parts and both matter. Find My Mac enables locating and locking. Find My network lets the Mac be found even when offline, by relaying anonymously through other Apple devices nearby.
Turn both on. There is no meaningful cost.
What it can do
Play a sound, useful when it is under a cushion.
Mark as Lost, which remotely locks the Mac, displays a message and a contact number, and prevents anyone using it.
Erase remotely, wiping the machine while keeping Activation Lock in force.
Show a location, when the machine can report one.
Enforce Activation Lock, so the Mac cannot be set up by anyone else without your Apple Account credentials.
That last one is the real protection. A locked Mac is worth very little, which is the point.
What it cannot do
Track it in real time. Location updates when the machine connects to a network. A Mac that is off, or has never connected since being taken, shows its last known position, which may be hours old.
Work reliably once the drive is erased by other means. Activation Lock survives a normal erase, and a machine taken apart is a different matter.
Locate to a precise address. Accuracy varies considerably. It has led people to neighbouring buildings.
Help if it was never enabled. This cannot be turned on remotely after the fact.
The offline finding network
Worth understanding, because it is the part that works surprisingly often.
A Mac that is asleep and offline can still be detected by nearby Apple devices, which relay an encrypted location to you. The relaying devices learn nothing, and neither does Apple.
It works when the machine has power and is asleep. It does not work when the machine is fully off or the battery is flat.
The privacy question
Find My also means Apple can, in principle, locate your devices, and locations are end-to-end encrypted so Apple cannot read them.
The more practical concern is people with access to your Apple Account seeing your devices. If you share an account with someone, they can see where your Mac is. That is one of several reasons not to share Apple Accounts, and to use Family Sharing instead. Family Sharing covers the difference.
Activation Lock, and the trouble it causes
Activation Lock is enabled automatically when Find My is on. It ties the Mac to your Apple Account so it cannot be reused without your credentials.
Two consequences worth knowing.
Before selling or giving away a Mac, sign out of iCloud first, then erase. Doing it in the other order can leave the machine locked and unusable for the new owner. Unpairing everything before a Mac leaves you covers the order.
When buying second-hand, check for the lock before paying. Ask the seller to erase it in front of you and confirm it reaches the setup screen. Buying a refurbished Mac covers the checks.
If you have already sold a Mac still attached to your account, remove it from your device list at icloud.com and the lock clears.
Using it
From another Apple device, the Find My app. From anywhere, icloud.com and sign in.
Worth doing once now, while nothing is lost, so you know where it is and what the options look like. Working it out for the first time under stress is worse.
Questions
Does it drain the battery? No meaningfully. Location reporting is infrequent and the offline network uses very little power.
Can I find a Mac that is switched off? Only its last known location. A sleeping Mac can be found via the offline network; a fully powered-off one cannot.
What if the thief signs out of my account? They cannot without your password. That is what Activation Lock prevents.
Should I erase it remotely straight away? If FileVault was on, the data is already protected, so marking as lost first keeps Activation Lock and the possibility of a location. Erase later if it is not recovered. Your Mac was stolen covers the sequence.