[altec3]

I'd say it's more about how thieves have started to use bluetooth scanners to determine if something very valuable is in your car. If they can tell a macbook is in your car, but your glovebox, center console or trunk are locked, they'll go to extra lengths to break into them.

[barbecue_sauce]

Can you get a bluetooth signal from a MacBook when its sleeping?

[gnicholas]

I believe you can, but not when it’s off. It may depend on your sleep settings (“wake for network activity” or “power nap”). I’m not an expert though — just my recollection.

[president]

Also "Allow Bluetooth devices to wake this computer" in Bluetooth settings.

[MrQuincle]

Then, would the computer not need to listen rather than broadcast?

PS: I know quite a lot about Bluetooth, although mostly about BLE. I don't see a reason why the device should be broadcasting anything. If it is scanning for BLE devices it can do "passive scanning". Is this about ordinary Bluetooth and is that different?

PS 2: Why is this different for Wifi? When a device is not connected to Wifi it sends probe requests for access points. My intuition would blame Wifi rather than Bluetooth. However, perhaps I don't know enough about old-fashioned Bluetooth. Or the device manufacturers have implementations that do not make sense from a privacy/security perspective.

[vorpalhex]

Bluetooth hosts aren't entirely passive as I understand it.

[snarfy]

Yes according to the article.