Or you can load your own firmware to any other embedded device with Bluetooth and also make it totally undetectable from iPhones by changing keys frequently and making it appear like multiple different AirTags. https://github.com/seemoo-lab/openhaystack/
I think the cat was out of the bag in a way on this one. Apple put in a good effort to stop abuse but the technology is in people hands now.
Of course, now that they have their own trackers, all Apple users are not only automatically opted into the Airtag network, they also made it almost impossible to opt out!
Talk about double standards.