Apple's Airtag's are a solution looking for a problem. You can't use them to "track lost items" while alerting thieves to their presence. Conversely you can't allow thieves to scan for their presence when they steal something. Their intended use case is pretty useless "find your stuff you've lost" I think, as it covers a small market segment compared to "LoJack, but cheap and fancy like Apple".
The solution requires a lot more governance, and puts Apple in charge of a "court system" with a lot of support cases.
* Every Airtag must have a registered owner. People are limited to the number of tags they're allowed to purchase and use.
* If an Airtag is lost by its owner, they can request it be located. If the Airtag is a significant distance from the owner, Apple must intervene.
* Apple must ask the user if they suspect the article is stolen. If Yes, the user can provide a police report and will be provided the location.
* If they suspect they misplaced the item, but not stolen, things get complicated.
* If the location is mobile since the owner departed the tag, and is tailing other Android/Apple iPhones, Apple will probably need to tell the owner too bad so sad, get a police report first.
* If its location is static since it departed contact with the owner's phone, Apple makes a judgement call as to if they believe it's a stalking situation. If the tag is tailing another Android/iPhone user, Apple should allow that person to have a setting on their phone to passively allow this case, allowing users to consent to being tracked.
There are other obvious edge cases, but I think this at least a start to how this useful technology could avoid stalking but provide for a wider variety of use cases.
And of course this breaks the e2e promise that Apple made, which _prevents_ them from getting NSLs when the government wants to track somebody... so, I don't see a good way out of this.