Yup, there was a project recently that used the airtag network to transmit data from a hardware keylogger. The computer could be totally gapped and the data still gets home via the typist's iPhone.

I am guessing this is the story: Keylogger leaks data via Apple AirTag network https://news.ycombinator.com/item?id=38126302

It's not airgapped if it has bluetooth access.

Presumably you stick the bluetooth antenna in the physical keylogger.

Sounds like a line from a conversation between a couple of pre-teen AIs.

I saw someone use this to track his mail state. They have a contact sensor inside their mailbox that rotates the broadcasted key based on the trigger count.

If the key changed, aka a new different device is visible, you know mail has been dropped in, very clever !

That is a fascinating project. Here is the link if anyone else is interested:

https://hackaday.com/2022/05/30/check-your-mailbox-using-the...

I wonder if the creator had neighbourhood style mailboxes down the road? If not this seems quite complicated solution for an object that is probably with range even BLE.

I tried building a mail sensor a couple of years ago where the mailbox was a fair distance from where I was living. I was not able to create a solution that didn't either have false positives or false negatives. For an outdoor object jostled by wind and rain it is harder than it seems.

I wish we had more / more easily accessible networks that let you do this.

Something that would let you send extremely tiny (<1kB) packets, using a wireless protocol that could be implemented extremely cheaply, piggybacking on the bandwidth of nearby internet-connected devices in a privacy-preserving way.

Amazon has a network like this called Sidewalk, using Alexa devices as gateways, but I don't think it's very open to third-party experimentation, and it's definitely not an interoperable standard on the gateway side.

Too bad Fon didn’t work out, it could have been a global mesh network useful for this kind of thing.

I don't particularly want my devices transmitting arbitrary packets from unknown parties.

Starlink's Swarm (or what ever they are calling it now) might be nice if they ever release the hardware and pricing.

How about LoRaWAN?