This seems like a problematic situation. In a vacuum I can see how they want to mitigate the stalking risks, but as of right now, unless you have a recently updated Apple device then, then you're completely ignored by the stalking mitigations. There's nothing official from Apple on the Google Play store that would mitigate that situation as well. This just seems like a low barrier to entry stalking tool on the extreme side of use cases for people Apple doesn't have business interests with.

I thought I read that the tag itself will start beeping if it's not near its owner for too long, and the tag has been moving around? Not sure what "too long" means, but if it's short enough, that should foil stalking attempts if the potential stalkee doesn't have an iDevice.

Edit: looks like it doesn't start beeping for three days (though Apple can change this server-side if they decide three days was a bad choice), which seems like way too long. A stalker could probably make good use of this in just a few hours, let alone three days.

I presume the location info is only collected if its marked as "lost" - at which point if the tag connects to apples network via someones phone, it'll prompt them. If its marked "lost" and sending location with no iphone nearby and is moved it beeps.

The stalking potential is greatly reduced if the victim has an android as the location will only be sent when its detected by an iphone.

The location information is updated whenever it is seen by an iDevice. The iDevice participates in this without its user's explicit permission or knowledge.

If the stalkee has an android they will never know. Their position will be snitched by every iDevice they come near.

From the Heinrich et al.paper:

"Lost devices. Devices that determine to be in a lost state start sending out BLE advertisements with a public key to be discovered by finder devices. Devices are considered to be lost when they lose Internet connectivity.

Third-party accessories [6] are small battery-powered devices that can be attached to a personal item and are set up through an owner device.

Accessories are determined to be lost when they lose their BLE connection to the owner device. Finder devices.

Finder devices form the core of the OF network. As of 2020, only iPhones and iPads with a GPS module are offering finder capabilities. Finder devices can discover lost devices and accessories by scanning for BLE advertisements. Upon receiving an OF advertisement, a finder creates an end-to-end encrypted location report that includes its current location and sends it to Apple’s servers."

Elsewhere, it is clear that this operates even when flight mode is enabled.

If you can't stand criticism of Apple, please fuck off back to reddit and fanboi there.

But you don't permanently see them, because the ID rolls over quite often to prevent tracking the beacon.

Conceivably the beacons co-operate in preventing tracking by conversing with iPhones nearby to store a random code supplied by the phone for a period of time, and allowing any iDevice to ask for the list. If your iDevice sees the same random code it transmitted to a stranger beacon appear in multiple time periods it knows it is colocated.

I would guess that the colocation feature would allow you to track devices actively (tailing someone).

Spies will have to be alert the potential for both exposure and tracking. Hopefully Apple commissions Spy Vs Spy ad campaigns!

My guess was simpler. If the phone sees a random tag for 30 minutes, then coincidentally that tag disappears but a new one shows up--for 30 minutes--and this keeps happening, then it's probably the same tag that's following you around. Especially if it's always about X meters away, or whatever.

Random tags passing by wouldn't maintain the same distance or RSSI, and they wouldn't be spaced perfectly apart in time either.

Of course I'm making assumptions here about the key rotation frequency, or even if it's a regular intervals. I guess if you're spending a lot of time in crowds, the rotating beacon that's with you would be hard to pick out of the myriad other beacons coming within range all the time. ("Was that a key rotation, or another person?")

I can see how that might work, but signal reception is always noisy. I doubt RSSI would be a reliable measure. You could partially wrap the AirTag in a scrunch of alfoil and it would mean every movement of the phone would massively change the reception, it would look like a variable distance.

Also, I wonder if it is a fixed time with no overlap? Because you could certainly track someone, eg through a shopping centre, by seeing when a beacon turns off and then listening to new beacons. Correlation would be trivial. And if the e.g. 30m clock is accurate then you could reidentify hours later by just listening to the rollover time, so they would have to vary the rollover at least.

I wonder about false alarms, because you can easily sit on commuter train for an hour and have someone next to you, even more so for long distance travel.